Bsc303 Chapter 1 Study Guide

Chapter 1
Being computer literate means being familiar enough with computers that you understand their capabilities and limitations Becoming a Savvy Computer User
-avoiding hackers and viruses
-protecting your privacy
-using the internet wisely
-being able to maintain, upgrade, and troubleshoot your computer
Spam- electronic junk mail
Software- the programs or instructions that tell the computer what to do
Information Technology (IT)- the set of techniques used in information handling and retrieval of information
Data Mining- the process of searching huge amounts of data with the hope of finding a pattern
Computer Forensics- applies computer systems and techniques to gather potential legal evidence
Radio Frequency Identification
Tags (RFID tags)- small electronic chips to track locations
Computers in Sports
-can be used to analyze performances to better a player’s game -done by showing what adjustments need to be made
Nanoscience- the study of molecules and structures that range in size from 1 to 100 nanometers
-nano stands for one-billionth Ex. Nanometer- one-billionth of a meter
Nanotechnology- the science revolving around the use of nanostructures to build devices on an extremely small scale
Affective Computing- computing that relates to emotion or deliberately tries to influence emotion
Emotional Social Prosthesis (ESP)- a system that is targeted to helping people who have autism
Patient Simulator- life-sized, computer controlled mannequins that are usually used for educational purposes
Digital Divide- refers to the “haves” and “have-nots” with regard to computer technology
RAM- random access memory
ROM- read only memory
DOS- disk operating system
GUI- Graphic user interface
The History of the PC
-first computer was in 1975 called Altair 8800 -was just 256 bytes
-the company that created the Altair, Micro Instrumentation and Telemetry Systems, received 4000 words for the PC
-short after the release of Altair, Microsoft wrote a program to translate user commands to commands a computer can understand for the Altair

CIS –Chapter 2 – Looking at Computers –Understanding the Parts * Computer is a data processing device that performs four major functions * It gathers data, or allows users to input it * It processes that data into information * It outputs data or information * It stores data and information * Data – representation of a fact, figure or idea – can be a number, a word, a picture, sound * Alone they mean little to you * Information – data that has been organized or presented in a meaningful fashion * Processing – manipulating or organizing data to information * Binary language – consists of two digits – o and 1, everything is broken down into binary (bit) * Eight binary digits combine to create one byte * Also KB, MB, GB, TB, PB, EB, ZB (1 GB = 1 billion bytes) * Google uses 20 PB a day * Computer uses a combo of hardware and software to process data into information * Hardware – any part of the computer you can physically touch * Software – set of computer programs that enables the hardware to perform different tasks * Application software – programs you use on the computer (ex- Word) * System software – programs enable your computer’s hardware and software to work together * OS – Operating System – program that controls the way in which your computer system functions * System unit and peripheral devices perform four main functions: * Input data * Process that data into information * Output the data and information * Store them * Input devices – enables you to enter data and instructions – keyboard, mouse, microphones, etc * QWERTY keyboard, also Dvorak keyboard – most common used letter on home keys * Virtual laser keyboard – transmit via Bluetooth – wireless connection * Numeric keypad, function keys, control key, windows key, multimedia buttons * Insert key / num lock /caps lock - toggle keys – function changes when you press it * Stylus – a pen shaped device that are used to tap on PDA’s * Tablet PC’s – touch-sensitive screen and handwriting recognition * Best wireless keyboards us RF (radio frequency) * optical mouse – laser, vs. track ball mouse, touchpad for laptop * Game controls are considered input devices, not mice * Magnetically shielded microphones – come with most computers * Unidirectional microphones – pick up sound from one direction – good for phone call * Omni directional microphones – pick up sounds from all directions – good for conference

* Monitors: * Cathode ray tube (CRT) – traditional computer monitor * Liquid crystal display (LCD) – notebook / flat screen – are lighter and more energy efficient * Legacy technology – ex – the CRT – technology that was once popular, but no longer is * Monitors are composed of pixel, each pixel has a red, blue and green sub pixel * 1600 x 1200 – means 1,600 vertical columns with 1,200 pixels in each * Passive matrix displays LCD- less expensive – fade over time * Active-matrix displays LCD – individually charged pixels – clearer, brighter, better viewing angle * Need to consider – viewing angle, contrast ratio, brightness, response time * Printers: * Impact printers – tiny, hammer like keys that strike the paper * Non-impact printers- inkjet and laser * Inkjet – quieter, faster and highly quality than impact printers * Laser – quick and quiet production and high quality – often used in schools * Plotters – large printers used to produce oversized pictures * Thermal printers – melting wax based ink onto ordinary paper or burning dots onto specially coated paper – used in airports for ticketing * Need to consider speed, resolution, colour output, memory, cost, ink cost * Sound: * Speakers, subwoofers, surround sound speakers * The System Unit: * System unit – is the metal or plastic case that contains the central electronics components of the computer – the processor, memory, circuit boards, storage devices * Most desktops are all in one computers * Sleep mode – all docs, etc remain in RAM (random access memory) available quickly * Hibernation mode – power saving – state of greatly reduced power, info protected from loss * Warm boot – restarting the system while its powered on * Cold boot – starting computer from shut off mode * The hard drive is nonvolatile storage – it holds data and instructions your computer needs permanently, even after computer is turned off * It is a non portable permanent storage * External hard drives – made hard drives portable via cables * CD-Rom drives – read cds, CD RW drives – read and write Cd’s, DVD RW – read and write DVD’s * Dvd’s can hold 25 x more data than a CD * Blu-Ray – can hold 50gb of data * Floppy disk drive – reads and writes to disks that hold limited data * Zip disk – wider opening than floppy – can carry much more data than floppy * Flash drives – aka – jump, USB, thumb drives – portable data storage – 16GB * Flash memory cards – let you transfer digital data between computer and digital cameras, PDA, smart phones, video cameras and printers * Ports – places on the system unit where peripheral devices attach to the computer so data can be exchanged between them and the OS * Serial ports – send data one bit at a time – were often used to connect modems – slow * Parallel ports – send data much faster (USB made them obsolete) * Universal Serial Bus (USB) ports – quickly transfer data * USB 2.0 ports – 40x faster than USB ports * Connectivity ports – give access to networks and the internet – enable computer to function as a fax machine * Ethernet port – connect computer to DSL or cable modem or a network * Modem port – telephone line port to internet * Also connect via Bluetooth and wireless connections * FireWire 800 is the fastest port available * VGA – Video graphic array – connect monitor * Super video (S-video) – and Digital visual interface (DVI) – connect to multimedia * Inside the System Unit: * Power supply – connected to wall voltage to power computer chips * Expansion cards – connection to other devices- sound and video * Modem card – provides the computer with a connection to the internet via phone * Network interface card (NIC) – high speed internet connection * Motherboard – largest – contains set of chips that power system, including CPU * CPU – Central Processing Unit – largest and most important chip in computer – brains * RAM – Random Access Memory – is temporary storage, is volatile storage, is lost when you turn the computer off- but quick access to data and commands when on * ROM – Read only memory – holds all the instructions the computer needs to start up * Is permanent (non-volatile storage location) * Mainframes – large, expensive computers that support hundreds of users simultaneously (ex –insurance company) * Supercomputers – can perform complex calculations extremely quickly * Main difference – super computer is designed to execute a few programs quickly, mainframe handle many programs, but slower * Embedded computers – specially designed computer chips that reside inside other devices * Ex- self contained computer devices – ex – thermostat in car * Ergonomics – an applied science concerned with designing and arranging things people use so that the people and things interact most efficiently and safely * How you set up your computer to minimize injury and discomfort * Position monitor correctly, adjustable chair, assume proper typing position, take breaks, ensure the lighting is adequate * Flexible screens – OLED – Organic light emitting displays – used in digital cameras – tend to use less power, making them better for portable devices – lightweight, inexpensive, flexible * Wearable screens – eyeglasses with displays built right in * Bistable screens – has the ability to retain its image even when the power is off = longer battery
CIS 1000 – Chapter Three – Using The Internet

The Internet

Internet – A network of networks that is the largest network in the world, connecting millions of computers from more than one hundred countries.
The Internet was created in the midst of the Cold War while the U.S was fighting the Soviet Union, because of the States’ need for computers to plan their activities.
The modern Internet evolved from an early U.S Government funded project called Advanced Research Projects Agency Network (ARPANET).
The World Wide Web is only one component of the Internet.
Web Browser – Software installed on a computer system that allows individuals to locate, view and navigate the web.
Web Site – A location on the Web

Communicating Through The Internet

E-Mail – Internet based communication in which senders and recipients correspond.
E-Mail Client – A software program that runs on a computer and is used to send and receive e-mail through the ISP’s server.
Instant Messaging – Program that enables users to communicate online in real time with others who are also online.
Newsgroup – A method of communication, similar to a discussion group or forum, in which people create threads, or conversations. In a thread, a newsgroup member will post messages and read and reply to messages from other members of the newsgroup.
Netiquette – The general rules of etiquette for Internet chat rooms and other online communication.

Web 2.0 Technologies

Web 2.0 – Tools and web based services that emphasize online collaboration and sharing among users.
Social Networking – A means by which people use the internet to communicate and share information among their immediate friends, and meet and connect with others through common interests, experiences and friends.
Blog – A personal log or journal posted on the web. Simple to create, manage and read.
Wiki – A type of web site that allows anyone visiting the website to change its content by adding, removing or editing the content.
Podcast – A clip of audio or video content that is broadcast over the internet using compressed audio or video files in formats such as MP3.
Really Simple Syndication – An XML-based format that allows frequent content on the World Wide Web.
Aggregators – A software program that goes out and grabs the latest update of web material according to your specifications.
Webcast – Is the broadcast of audio or video content over the Internet.

Web Entertainment: Multimedia and Beyond

Multimedia – Anything that involves one or more forms of media plus text.
Streaming Audio – Technology that enables audio files to be fed to a browser continuously. This lets users avoid having to download an entire file before listening.
Plug-In – A small software program that plugs in to a web browser to enable specific function.

Conducting Business over the Internet: E-Commerce
E-Commerce – The process of conducting business online for purposes ranging from fund raising to advertising to selling products.
Approx. $100 billion each year is spent on goods purchased over the internet.

Accessing the Web: Web Browsers
Web Browser – Software installed on a computer system that allows individuals to locate, view and navigate the web (Internet Explorer, Mozilla Firefox)

Getting Around the Web
Uniform Resource Locator – A web sits unique address; an example is Microsoft.com
HyperText Transfer Protocol Secure (HTTP) – The protocol that allows files to be transferred from a web server so that you can see them on your computer by using a browser.
Host – The location that maintains the computers that store the Web site files.
Path – Is what identifies each different page within a particular web site.
Hyperlink – A type of specifically coded text that, when clicked, enables a user to jump from one location to another.
Breadcrumb List – A list that shows the hierarchy of previously viewed web pages within the web site that you are currently visiting.
Favorites – Places an easily retrievable URL in a list in your browser’s toolbar.

Searching the Web Effectively
Search Engine – Is a set of programs that searches the Web for keywords and then returns a list of web sites on which those key words are found.
Spider – A program that constantly collects information on the web, following links in web sites and reading web pages.
Boolean Operators – Words such as OR, AND that describe relationship between key words in a search.
Internet Backbones – The largest and fastest pathways of the Internet.

Connecting to the Internet

Dial-up Connection – A connection to the Internet using standard telephone line.
Digital Subscriber Line – A type of connection that uses telephone lines to connect to the Internet and that allows both phone and data transmissions to share the same line.
Modem – A communication device that works to translate digital data into an analog signal and back again.
Aircard = Cellular modem
The Future of the Internet
Large Scale Network – A program created by the U.S government, the objective of which is to fund the R&D of cutting edge networking technologies.

Key Terms | Chapter 4 – Application SoftwarePrograms That Let You Work and Play | accounting software | An application program that helps business owners manage their finances more efficiently by providing tools for tracking accounting transactions such as sales, accounts receivable, inventory purchases, and accounts payable. | application software | The set of programs on a computer that helps a user carry out tasks such as word processing, sending e-mail, balancing a budget, creating presentations, editing photos, taking an online course, and playing games. | audio editing software | Programs that perform basic editing tasks on audio files such as cutting dead air space from the beginning or end of a song or cutting a portion from the middle. | beta versions | Early versions of software programs that are still under development. Beta versions are usually provided free of charge in return for user feedback. | bloatware | The pre-installed software (often trial versions) on a new computer. | Computer-aided design (CAD) | 3-D modeling programs used to create automated designs, technical drawings, and model visualizations. | copyleft | A simplified licensing scheme that enables copyright holders to grant certain rights to a work while retaining other rights. | course management software | Programs that provide traditional classroom tools such as calendars and grade books over the Internet, as well as areas for students to exchange ideas and information in chat rooms, discussion forums, and using e-mail. | custom installation | Installing only those features of a software program that a user wants on the hard drive, thereby saving space on the hard drive. | customer relationship management (CRM) software | A business program used for storing sales and client contact information in one central database. | database software | An electronic filing system best used for larger and more complicated groups of data that require more than one table, and where it’s necessary to group, sort, and retrieve data, and to generate reports. | desktop publishing (DTP) software | Programs for incorporating and arranging graphics and text to produce creative documents. | digital video-editing software | Programs for editing digital video. | drawing software (or illustration software) | Programs for creating or editing two-dimensional line-based drawings. | Enterprise Resource Planning (ERP) system | Software used to control “back-office” operations and processing functions such as billing and inventory management. ERP systems are implemented by third-party vendors and matched directly to the specific needs of a company. | entertainment software | Programs designed to provide users with entertainment; computer games make up the vast majority of entertainment software. | Entertainment Software Rating Board (ESRB) | A self-regulatory body established in 1994 by the Entertainment Software Association that rates computer and video games according to the age appropriateness of content. | financial planning software | Programs for managing finances, such as Intuit’s Quicken and Microsoft Money, which include electronic checkbook registers and automatic bill payment tools. | freeware | Any copyrighted software that can be used for free. | frequently asked questions (FAQs) | A list of answers to the most common questions. | full installation | Installing all the files and programs from the distribution CD to the computer’s hard drive. | image-editing software (sometimes called photo-editing software) | Programs for editing photographs and other images. | integrated help | Documentation for a software product that is built directly into the software. | integrated software application | A single software program that incorporates the most commonly used tools of many productivity software programs into one integrated stand-alone program. | macro | A small program that group a series of commands to run as a single command. | mapping programs | Software that provides street maps and written directions to locations. | multimedia software | Programs that include image, video, and audio editing software, animation software, and other specialty software required to produce computer games, animations, and movies. | online mapping service | An alternative to more traditional mapping software programs; easily accessible with any Internet connection and updated more frequently than offline services. Examples include MapQuest, Yahoo! Maps, Google Maps, and Google Earth. | open source software | Program code made publicly available for free; it can be copied, distributed, or changed without the stringent copyright protections of proprietary software products. | personal information manager (PIM) software | Programs such as Microsoft Outlook or Lotus Organizer that strive to replace the various management tools found on a traditional desk, such as a calendar, address book, notepad, and to-do lists. | presentation software | An application program for creating dynamic slide shows, such as Microsoft PowerPoint or Corel Presentations. | productivity software | Programs that enable a user to perform various tasks generally required in home, school, and business. This category includes word processing, spreadsheet, presentation, personal information management (PIM), and database programs. | program | A series of instructions to be followed by a computer to accomplish a task. | project management software | An application program such as Microsoft Project that helps project managers easily create and modify project management scheduling charts. | proprietary software | A program that is owned and controlled by the company it is created by or for. | shareware | Software that enables users to “test” the software by running it for a limited time free of charge. | simulation software | Software, often used for training purposes, which allows the user to experience or control an event as if it is reality. | software | The set of computer programs or instructions that tells the computer what to do and enables it to perform different tasks. | Software as a Service (SaaS) | Software that is delivered on demand over the Internet. | software license | An agreement between the user and the software developer that must be accepted prior to installing the software on a computer. | software piracy | Violating a software license agreement by copying an application onto more computers than the license agreement permits. | software suite | A collection of software programs that have been bundled together as a package. | software updates (or service packs) | Small downloadable software modules that repair errors identified in commercial program code. | speech-recognition software (or voicerecognition software) | Software that translates spoken words into typed text. | spreadsheet software | An application program such as Microsoft Excel or Lotus 1-2- 3 that enables a user to do calculations and numerical analyses easily. | system requirements | Minimum storage, memory capacity, and processing standards recommended by the software manufacturer to ensure proper operation of a software application. | system software | The set of programs that enables a computer’s hardware devices and application software to work together; it includes the operating system and utility programs. | tax-preparation software | An application program such as Intuit’s TurboTax and H&R Block’s TaxCut for preparing state and federal taxes. Each program offers a complete set of tax forms and instructions as well as expert advice on how to complete each form. | template | A form included in many productivity applications that provides the basic structure for a particular kind of document, spreadsheet, or presentation. | vertical market software | Software that is developed for and customized to a specific industry’s needs (such as a wood inventory system for a sawmill) as opposed to software that is useful across a range of industries (such as word processing software). | virtual reality programs | Software that turns an artificial environment into a realistic experience. | Web page authoring software | Programs you can use to design interactive Web pages without knowing any HyperText Markup Language (HTML) code. | wizards | Step-by-step guides that walk you through the necessary steps to complete a complicated task. | word-processing software | Programs used to create and edit written documents such as papers, letters, and résumés. |
Chapter 4 Study Questions
1. What’s the difference between application software and system software?
System software is the software that helps run the computer and coordinates instructions between application software and the computer’s hardware devices. System software includes the operating system and utility programs. Application software is the software you use to do everyday tasks at home, school, and work. Application software is productivity software, such as word-processing and finance programs; media software, such as those used for image editing; home/entertainment, such as games or educational programs; and business software.
2. What kinds of applications are included in productivity software I might use at home?
Productivity software programs include word-processing, spreadsheet, presentation, personal information manager (PIM), and database programs.
You use wordprocessing software to create and edit written documents. Spreadsheet software enables you to do calculations and numerical and what-if analyses easily. Presentation software enables you to create slide presentations. Personal information manager (PIM) software helps keep you organized by putting a calendar, address book, notepad, and to-do lists within your computer. Database programs are electronic filing systems that allow you to filter, sort, and retrieve data easily. Individuals can also use software to help with business-like tasks such as preparing taxes or managing personal finances.
3. What are the different types of multimedia software?
Multimedia software includes digital image, video- and audio-editing software, animation software, and other specialty software required to produce computer games. A wide variety of software programs is used to play, copy, record, edit, and organize MP3 files. Modern users have so many audio, video, and image files that there are a number of software solutions for organizing and distributing these types of files.
4. What are the different types of entertainment
software?
Beyond the games that most of us are familiar with, entertainment software includes virtual reality programs that use special equipment to make users feel as though they are actually experiencing the program in a realistic 3-D environment.
5. What is reference software?
Software applications that act as sources for reference materials, such as the standard atlases, dictionaries, and thesauri, are referred to collectively as reference software. A lot of reference software on the market incorporates complex multimedia.

6. What are the different types of drawing software?
Drawing software lets you create and edit line-based drawings to produce both imaginative and technical illustrations. Floor plans, animations, and mind-maps are some of the types of images that can be created.
7. What kinds of software do small and large businesses use?
Many businesses, including home businesses, use general business software, such as Business Plan Pro and Marketing Plan Pro, to help them with tasks common to most businesses. In addition, businesses may use specialized business software (or vertical market software) that is designed for their specific industry.
8. Where can I go for help when I have a problem with my software?
Most software programs have a Help menu built into the program with which you can search through an index or subject directory to find answers. Some programs group those most commonly asked questions in a single frequently asked questions (FAQ) document. In addition, vast resources of free or fee-based help and training are available on the Internet or at booksellers.
9. How can I purchase software or get it for free?
Almost every new computer system comes with some form of software to help you accomplish basic tasks. All other software you need to purchase unless it is freeware or open-source code, which you can download from the Internet for free. You can also find special software called shareware that lets you run it free of charge for a test period. Although you can find software in almost any store, as a student you can purchase the same software at a reduced price with an academic discount.
10. How do I install, uninstall, and open software?
When installing and uninstalling software, it’s best to use the specific Add/Remove Program feature that comes with the operating system. Most programs are installed using an installation wizard that steps you through the installation. Other software programs may require you to activate the setup program, which will begin the installation wizard. Using the Add/Remove Programs feature when uninstalling a program will help you ensure that all ancillary program files are removed from your computer.

Chapter 5

System Software Basics
Basic types of software on computers: 1. Application Software – software you use to do everyday tasks at home and at work 2. System Software – set of programs that helps run the computer and coordinates instructions between application software and the computer’s hardware devices

What does an operating system do?
Two primary types of programs system software consists of: 1. Operating System (OS) – a group of programs that controls how your computer system functions * Manages the computer’s hardware, including the processor [aka central processing unit (CPU)], memory, and storage devices, as well as peripheral devices such as the monitor and printer * Provides a consistent means for software applications to work with the CPU * Responsible for the management, scheduling, and coordination of tasks as well as system maintenance * First interaction is the user interface – the features of the program such as the desktop, icons, and menus that allow the user to communicate with the computer system 2. Utility Program – a small program that performs many of the general housekeeping tasks for the computer, such as the system maintenance and file compression

Do all computers have operating systems? * All computers (notebooks to supercomputers), cell phones, game consoles, automobiles, and some other appliances have an operating system * Computers can not operate without an OS * OS coordinates the flow of data and information through the computer system by coordinating the hardware, software, user interface, processor, and system memory

Are all operating system alike? * Many types of operating systems exist * Some don’t require user intervention (in household appliances and car engines) * Some are proprietary systems (developed specifically for the devices they manage) * Some are for personal and business use, others coordinate resources for many users on a network * Traditionally classified into categories, depending on the number of users they served (single or multiple users) and the tasks they performed (single or multitask) * As devices converge in their functionalities, OSs become more powerful and the traditional categorization blurs * Microsoft Disk Operating System (MS-DOS) – first widely installed operating system for personal computers that was highly user-unfriendly * Required specific commands to be typed and did not have the option to click on icons or choose from menus or lists * Apple’s Mac OS and Microsoft’s Windows replaced DOS because it allowed single user to multitask * Networking capabilities were added to personal computer operating systems to facilitate sharing peripheral devices and Internet access among multiple computers at home * Single-user systems have now become multitask operating systems for multiusers * Similar transitions are taking place with mobile devices, while cell phones and PDAs converge to smartphones and incorporate the functionalities of cameras and personal media players

Types of Operating Systems * Categorized depending on the type of devices they are installed

Real-Time Operating Systems
Why do machines with built-in computers need an operating system? * Machinery required to perform a repetitive series of specific tasks in an exact amount of time require a real-time operating system (RTOS) * RTOS aka embedded systems require minimal user interaction * Programs are written specifically for the needs of devices and their functions * No commercially available standard RTOS software programs * A program with a specific purpose * Must guarantee certain response times for particular computing tasks; otherwise the machine is useless * Devices that perform regimented tasks or record precise results like measurement instruments in science, defense, and aerospace industries use RTOSs * E.g. digital storage oscilloscopes and the Mars Reconnaissance Orbiter

Where else are RTOSs in use today? * Found in devices such as fuel-injection systems in car engines, inkjet printers, VoIP phones, and some medical devices (see Figure 5.2 on pg. 210), as well as common appliances like washing machines, dryers, and furnaces * Found in man types of robotic equipment * Television stations use robotic cameras with RTOS that glide across a suspended cable system to record sports events from many angles

What kind of operating system controls a simple cell phone? * Simple cell phones are separate, single-function devices which only require OSs that perform one task at a time * Cell phones have their own proprietary embedded OS

Operating Systems for Networks, Servers, and Mainframes
What kind of operating system do networks use? * Multiuser Operating System (aka network operating system) – enables more than one user to access the computer system at one time by efficiently handling and prioritizing requests from multiple users * Networks (groups of computers connected to each other for the purposes of communicating and sharing resources) require a multiuser OS because many users simultaneously access the server, which is the computer on a network that manages network resources such as printers * Examples of Network OSs include: the latest version of Microsoft Windows and Mac OS X * Enable users to set up networks in homes and small businesses * In larger networks, a network OS is installed on the server and manages all user requests, ensuring they do not interfere with each other * E.g. a network where users share a printer, the OS is responsible for managing the printer requests and making sure they are processed one at a time * E.g. of network OSs include: Linux and UNIX

What is UNIX? * UNIX – a multiuser multitask OS used as a network OS, primarily with mainframes * Developed in 1969 by Ken Thompson and Dennis Ritchie of AT&T’s Bell Labs * UNIX code as originally not proprietary (no company owned it) * Was later licensed to the Santa Cruz Operation Group * UNIX is a brand that belongs to the company The Open Group, but any vendor that meets testing requirements and pays a fee can use the UNIX name * Examples of UNIX systems currently available in the marketplace * HP/UX from Hewlett-Packard * Solaris from Sun * AIX from IBM

What other kinds of computers require a multiuser operating system? * Mainframes are often used by large corporations with hundreds and thousands of employees and super computers * Mainframe – responsible for storing, managing, and simultaneously processing data from all users * Mainframe OS fall into the multiuser category * Examples include: * UNIX * IBM’s IBM i and z/OS

Operating Systems for Mobile Devices
What kind of operating system do smartphones use? * Smartphones allow users to make and answer phone calls, and has productivity features, in addition to features found on personal media payers and cameras as well as the ability to connect to eh Web * The most common OSs that can be found on smartphones include Symbian by Nokia, BlackBerry by RIM, Windows Mobile by Microsoft, and iPhone OS X by Apple, Android by Google, and webOS by Palm * iPhone’s OS X and Palm Pre’s webOS enable users to run more than one application currently

Do gaming consoles and personal media players require an operating system? * All consoles require a form of customized system software that is developed specifically for the particular device * System software includes system programs aka firmware – that controls the device, as well as other programs that come with the personal media player or the gaming device * Programs included with most portable media players allow users to manage music files on the player and to rip audio CDs * Game console OSs support Web browsing and file storage of media and photos as well as playing DVDs and games

Operating Systems for Personal Computers
What is the Microsoft Windows operating System? * 1995 – Microsoft released Windows 95, a comprehensive update that made changes to the user interface and incorporated multitasking capabilities * Windows XP – provided networking capabilities in its consumer editions * Windows 7 – newest release of Microsoft’s OS which follows Windows Vista and builds on the security and user interface upgrades that Vista provided * Gives users with touch-screen monitors the ability to use touch commands o scroll, resize windows, pan, and zoom * Overtime, Windows concentrated on increasing user functionality and friendliness, improving Internet capabilities, and enhancing file privacy and security

What is the difference between the various editions of Windows 7 operating systems? * Different versions exist to accommodate different users: * Home users (Started, Home Basic, Home Premium) * Business users (Professional and Enterprise) * Combination users (Ultimate) * 32-bit version – built for computers that have up to 4GB of RAM * 64-bit version – for computers that have more than 4GB of RAM
(See figure 5.4 on p.g. 212 for an outline of features and benefits of each edition of Windows 7)

What is the Mac Operating System? * 1984 – Mac OS – first commercially available OS to incorporate a graphical user interface (GUI) with user-friendly point-and-click technology

Does it matter what operating system is on my computer? * Type of processor in the computer determines which OS a particular personal computer uses * Computer platform – combination of OS and processor * If two computers have processors form the same manufacturer, the two operating systems (Windows and Mac OS_ are not really interchangeable * Without using special software, if you attempted to load Microsoft Windows on a Mac, the processor in the Mac would not understand the Windows OS and would not function properly * Boot Camp which is available with Mac OS C Snow leopard, allows you to run Windows on a Mac while also running OS X * Most application software is platform dependent (special Mac versions of Microsoft Office, Adobe Photoshop Elements, Intuit Quicken, and other “traditional” PC software applications) * PCs and Macs can be networked so that they can easily share files and even peripherals, such as printers, scanners, and cameras

Can I have more than one operating system on my computer? * The generous size of the hard drives, in addition to some additional software capabilities, enable users to: run multiple versions of OS on a single machine * In order to run two versions of Windows, or a Windows-Linux setup, you just need to separate the hard drive into different sections (partitions) and install the second operating system in the new partition

What is Linux? * Linux – an open source OS designed for use on personal computers and as a network OS * Open source software is freely available for developers to use or modify as based on the central programming code of an OS, and the rest of the code is from the GNU (“g-noo”) Project and other sources * Is gaining a reputation as a stable OS that is not subject to crashes or failures * Can be tweaked quickly to meet virtually any new operating system need

Where else is Linux used? * Android, the new OS developed by Google is Linux based * Because the overall size of Android if much smaller than that of Windows, many netbook users choose to use it in place of the factory-installed Windows operating system * MeeGo, a joint project between Nokia and Intel is also Linux based

Where can I get Linux? * Download open source versions of Linux for free form the internet * Distributors include: Mandriva, Ubuntu, Fedora, Suse, Debian GNU/Linux, and Gentoo Linux * Several versions of Linux are more proprietary and must be purchased * These versions come with support and other features that are not generally associated with the open source Linux * Red Hat has been packaging and selling versions of Linux since 1994 and is probably the best-known Linux distributor

What the Operating System Does * Coordinates and directs the flow of data and information through the computer system (see figure 5.7 on p.g. 214) * The OS performs several specific functions * Provides a way for the user to interact with the computer * Manages the processor, or CPU * Manages the memory and storage * Manages the computer system’s hardware and peripheral devices * Provides a consistent means for software applications to work with the CPU

The User Interface
How does the operating system control how I interact with my computer? * Operating system provides a user interface that enables you to interact with the computer * Command-driven interface – is one in which you enter commands to communicate with the computer system * PCs were used primarily in business and by professional computer operators because DOS commands were not easy to understand * Menu-driven interface – is one in which you choose commands from menus displayed on the screen * Eliminated the need for users to know every command because they could select most of the commonly used commands from a menu

What kind of interface do operating systems use today? * OSs use graphical user interface, or GUI * GUIs – display graphics and use the point-and-click technology of the mouse and cursor, making them much more user-friendly * Linux does not have a single GUI, it allows users to freely choose interfaces such as GNOME and DKE * GNOME – allows you to select which interface you’d like your system to have

Processor Management
Why does the operating system need to manage the processor? * When using a computer, you are asking the CPU to perform several tasks at once * The OS arranges for the execution of all activities in a systematic way, creating the appearance that everything is happening simultaneously * OS assigns a slice of its time to each activity that requires the processor’s attention * It then switches among different processes millions of times a second to make it appear that everything is happening seamlessly

How exactly does the operating system coordinate all the activities? * Many different devices in the computer system are involved when a documents is created and printed in word while watching a Blu-ray movie * Every keystroke, every mouse click, and each signal to the printer and from the Blue-ray drive creates an action, or event, in the respective device to which the operating system responds * Sometimes events occur sequentially or involve two or more devices working concurrently * OS switches back and forth among processes, controlling the timing of events the processor works on to make it seem like everything is working at the same time * Interrupt – a unique signal that is sent when you are printing a document that tells the OS that it is in need of immediate attention * Interrupt handler – a special numerical code that prioritizes the requests * All devices have their own type of interrupt * These requests are places in the interrupt table in the computer’s primary memory (random access memory, or RAM) * OS processes the task assigned a higher priority before processing a task that has been assigned a lower priority – preemptive multitasking * When the interrupt is received from the printer, the OS pauses the CPU from its typing activity and form the Blu-ray activity, and puts a “memo” in a special location in RAM called a stack * Memo – a reminder of what the CPU was doing before it started to work on the printer request * CPU retrieves the printer request from the interrupt table and begins to process it * CPU goes back to the stack, retrieves the memo it places about the keystroke or Blu-ray activity, and returns to that task until it is interrupted again, in a very quick and seamless fashion

What happens if there is more than one document waiting to be printed? * OS also coordinates multiple activities for peripheral devices such as printers * When the processor receives a request to send information to the printer, it first checks with the operating system to ensure that the printer is not already in use * If it is, the OS puts the request in another temporary storage area in RAM, called the buffer * Request then waits in the bugger until the spooler – a program that helps coordinate all print jobs currently being sent to the printer, indicates the printer is available * If more than one print jobs is waiting, a line (or queue) is formed so that the printer can process the requests in order

Memory and Storage Management
Why does the operating system have to manage the computer’s memory? * As the OS coordinates the activities of the processor, it uses RAM as a temporary storage area for instructions and data the processor needs * Processor then accesses these instructions and data from RAM when it is ready to process them * OS is responsible for coordinating the space allocations in RAM to ensure that there is enough space for all of the pending instructions and data * It then clears the items from RAM when the processor no longer needs them

Does the amount of RAM on a system control the type of OS I get? * Many personal computer systems that are reasonably prices provide 8GB of RAM or more * Systems that offer 4GB or more of RAM will feature a 64-bit version of Windows * Not all applications and devices are compatible with 64-bit system, you’ll need to make sure that all hardware and software programs are updated to work well with the 64-bit version of your OS * Windows 7 Upgrade Advisor – downloadable free program checks to determine whether a computer is compatible in all respects with Windows 7 including 64-bit compatibility * If there is incompatibility, Windows 7 allows you the option of running in a compatibility mode to emulate a 32-bit system

Can my system ever run out of RAM? * RAM has limited capacity * Most computers sold for home use have between 2 and 12GB of RAM * If you install and use software with greater RAM requirements, your system might not respond well * As you add and upgrade software and increase your usage of the computer system, you will likely find that the amount of RAM you once found to be sufficient is no longer enough

What happens if my computer runs out of RAM? * When there is not enough Ram for the OS to store the required data and instructions, the OS borrows from the more spacious hard drive * Virtual memory – process of optimizing RAM storage by borrowing hard drive space
(see figure 5.11 on p.g. 219) * Swap file (page file) – a temporary storage area on the hard drive that is used when more RAM is needed (the OS swaps out form RAM the data or instructions that have not been recently used and moves them to this area * if data or instructions in the swap file are needed later, the OS swaps them back into active RAM and replaces them in the hard drive’s swap file with less active data or instructions – paging

Can I ever run out of virtual memory? * Only a portion of the hard drive is allocated to virtual memory * You can manually change this setting to increase the amount of hard drive space allocated, but eventually your computer system will become sluggish as it is forced to page more and more often * Thrashing – excessive paging * Solution to this problem is to increase the amount of RAM in your system so that it will not be necessary for it to send data and instructions to virtual memory

How does the operating system manage storage? * If it weren’t for the OS, the files and applications saved to the hard drive and other storage locations would be an unorganized mess * OS has a file-management system that keeps track of the name and location of each file you save and the programs you install

Hardware and Peripheral Device Management
How does the operating system manage the hardware and peripheral devices? * Device driver – a special program that comes with any device attached to your computer * Facilitates communication between the hardware device and the OS * OS must be able to communicate with every device in the computer system * Device driver translates the device’s specialized commands into commands that the OS can understand, and vice versa * Devices would not function without the proper device drivers because the OS would not know how to communicate with them

Do I always need to install drivers? * Plug and Play (PnP) devices – devices whose drivers are included in Windows (flash drives, mice, keyboards, digital cameras etc.) * PnP – a software and hardware standard that Microsoft created with the Windows 95 OS * Designed to facilitate the installation of new hardware in PCs by including in the OS the drivers these devices need in order to run * Incorporating new devices into your computer system will now seem automatic * Enables users to plug a new device into a port on the system unit, turn on the computer, and immediately play (use) the device * OS automatically recognizes the device and its driver without any further user manipulations of the system

What happens if the device is not Plug and Play? * When installing non-PnP devices, you will be prompted to insert the driver that was provided with the device

Can I damage my system by installing a device driver? * When you install a driver, your system may become unstable (that is, programs may stop responding, certain actions may cause a crash or the device or he entire system may stop working) * Windows has a Roll Back Driver feature that removes a newly installed driver, and replaces it with the last one that worked, to remedy the problem (see figure 5.12 on p.g. 220) * Roll Back Driver – found by accessing the Drive Manager dialog box under System and Maintenance in the Control Panel

Software Application Coordination
How does the operating system help application software run on the computer? * Application software feeds CPU instructions to process data, takes form as a computer code * All computer programs needs to interact with the CPI, programs must use the code that the CPU recognizes * Application Programming Interface (API) is blocks of code in the OS that application software needs in order to interact with the OS

What are the advantages of using APIs? * Programmers only need to refer to API blocks when creating applications * Prevent redundancies in software code * Makes it easier for software developers to respond to changes in the OS * Applications sharing these formats can easily exchange data with each other

The Boot Process: Starting Your Computer * Book Process – loads the OS into the RAM * The Steps in the Boot Process 1. The basic input/output system (BIOS) is activated by powering on the CPU * BIOS is a program that manages the exchange of data between the OS and all the input and output devices * BIOS is also responsible for loading the OS into RAM 2. The BIOS checks that all attached devices are in place (called a power-on self-test or POST) * Ensures essential peripheral devices are attached and operational * Ensure that memory chips are working properly * CMOS – Complementary Metal-Oxide Semiconductor contains information about the system’s memory, types of disk drives, and other essential input and output hardware * If the results of the POST compare favourably to the CMOS, boot process continues 3. The operating system is loaded into the RAM * Searches for a drive containing the system files, when located it is loaded into RAM, once it is loaded the kernel is loaded * The Kernel (or supervisor program) is the essential component of the OS, responsible for managing the processor and all other components of the system. It is said to be “memory resistant” * Less critical parts of the OS stay on the hard drive and are copied over to RAM on an as-needed basis, these programs referred to as “resistant” * Once kernel is loaded, the OS takes over control of the computers functions 4. Configuration and customization setting are checked * CMOS checks the configuration of memory and essential peripherals in the beginning of the boot process * OS checks the registry for configuration of other system components * Registry – contains all of the different configurations used by the OS and by other applications, contains the customized settings you put into place * Networks found in places such as colleges, OSs serves many people therefore need a user and password for log in * Authentication – the verification of your login name and password

Handling Errors in the Boot Process
What should I do if my computer doesn’t boot properly? * If you have recently uninstalled new software – try to uninstall it * Restart your computer in safe mode

What is Safe mode? * A special diagnostic mode designed for troubleshooting errors * Only essential devices function (mouse, keyboard, etc.) * System runs on most basic graphics * You can still use device manager – lets you view and change the properties of all devices attached to your computer * Boots windows with only the original Microsoft windows drivers that are required to boot the computer * Last known good configuration – start your computer by using the registry information that was saved during the last shut-down * If all other attempts to reboot fail, try systems restore to roll back to a past configuration

What should I do if my keyboard or another device doesn’t work after I boot my computer? * Generally resolve issue by rebooting * If it still persists, check OS’s website for any patches that may resolve the issue

The Desktop and Windows Features * Desktop is the first interaction you have with the OS and the first image you see on your monitor

What are the main features of the Windows desktop and Start menu? * Desktops let you customize it to meet your individual needs * On the desktop you’ll find * Recycle Bin – location for deleted files and folders form the C: drive only * Gadgets – an easy-to-use miniprogram that gives you information at a glance or quick access to frequently used tools including weather information, calendar items, calculators, games, photo albums etc. * Taskbar – displays open and favourite application for easy access * Documents * In the Windows 7 Start menu, you’ll find: * Documents – a convenient organizational tool that enables you to keep all your documents in one place * Computer – provides easy access to disk drives and system and network devices * All Programs – provides access to all programs available in the system

How does the Mac desktop compare with Windows? * Both use windows (rectangular boxes that contain programs displayed on the screen), menus (lists of commands that appear on the screen), and icons (pictures that represent an object such as a software application or a file or folder) * Both have streamlined mechanisms to access commonly used applications * Macs have a Dock and a Dashboard with widgets * Widgets – mini-application that enables quick access to frequently used tools and activities

What are common features of a window? * Most programs have windows that include toolbars, which have icons (shortcuts to frequently used tasks) and scrollbars (bars that appear at the side or bottom of the screen that control which part of the information is displayed on the screen) * Newer versions of Microsoft Office have begun to organize toolbars into a ribbon interface * Ribbon is further organized into task-specific tabs with relevant commands

How can I see more than one window on my desktop at a time? * Arrange windows on a desktop by arranging separate windows so that they sit next to each other horizontally or vertically * You can also cascade them so they overlap one another, or you can resize two open windows so that they appear on the screen at the same time * Windows Vista offers two ways to navigate through open windows * To see live thumbnail images of open windows, press Alt + Tab to access Windows Flip * Pressing the Windows key + Tab initiates the Windows Flip 3D feature

Can I move or resize the windows once they are tiled? * Regardless of whether the windows are tiled, you can resize them and move them around the desktop

Organizing Your Computer File Management * OS enables file management, which entails providing organizational structure to the computer’s contents * OS allows you to organize the contents of your computer in a hierarchical directory structure that includes files, folders, libraries, and drives

Organizing Your Files
What exactly is a file? * A file is a collection of related pieces of information stored together for easy reference * A file in an OS is a collection of program instructions or data that is stored and treated as a single unit * Files can be generated from an application such as Word document or an Excel workbook * It can represent an entire application, a Web page, a set of sounds, or an image * Are stored on the hard drive, a flash drive, or another permanent storage medium * As the # of files stored increases, it becomes more important to keep them organized in folders and libraries * Folder is a collection of files * Library is a collection that gathers files from different locations and displays them as if they were all saved in a single folder, regardless of where they are actually physically stored

How does the operating system organize files? * Windows organizes contents of your computer in a hierarchical structure comprising drives, folders, subfolders, and files * Hard drive represented as the C drive is where you permanently store most of your files * A drive – reserved for a floppy drive * Other drives found in your computer are represented by other letters (D,E,F … )

How is the hard drive organized? * C drive is where all files are stored * C drive is the top of the filing structure of the computer system referred to as the root directory * The Windows OS creates special folders called Document, Pictures, Music, and Videos, where you may begin to store and organize your text, image, audio, and video files

How can I easily locate and see the contents of my computer? * Windows Explorer is the main tool for finding viewing, and managing the contents of your computer * It shows the location and contents of every drive, folder, and file * It is divided into two panes, or sections * Navigation Pane (left) shows the contents of your computer in a traditional hierarchical tree structure * It displays all the drive of the system as well as other commonly accessed areas such as the Desktop, Libraries, and Documents, Music, Pictures, and Video folders

How should I organize my files? * Creating folders is the key to organizing your files because folders keep related documents together * Inside each folder you can create subfolders * Grouping related files into folders makes it easier for you to identify and find files * Grouping files in a folder also allows out o move them more efficiently so you can quickly transfer critical files needing frequent backup

Viewing and Sorting Files and Folders
Are there different ways I can view and sort my file and folders? * When a folder is open in Windows, the toolbar at the top displays a “View” button

Tiles View: * Displays the tiles and folders in a list form made of icons * Each icon represents the application associated with the file * It includes the name, size of the file, and other customizable data * Also displays picture dimensions, handy for webpage developers

Details View: * The most interactive view * Displayed in a list form, with additional file information in columns beside it * Can be sorted to display all the folders by any of the headings (e.g. By name, type dates modified, or file size)

List View: * Another display of icons and names that are even smaller than in tiles view * A good view for when you have a lot of content in the folder, to view most of it at once

Small and Medium Icons Views: * Displays files and folders in list form but they are either small or medium sized * Additional information is displayed in a ScreenTip (info that appears when your cursor is over the file)

Large and Extra Large Icons View: * Large icon views show the contents of the folders as small images * Extra-large icon views show folder contents and other icons as even larger images * Best use if your folder contains pictures, PowerPoint presentations (easy to tell which presentation is which) * The scale feature is also used to adjust the icon sizes further * A preview pane allows you to view the first page without opening it completely * For folders with MP3 files, downloading the CD image can help identify it easily

What’s the best way to search for a file? * Newer version of Windows include an Instant Search which is found on the start menu * It searches through your hard drive to locate files that match your criteria * Can be the full name or part of a phrase, you can also narrow it down by providing the information about what type of file it is, which application created it, how long ago the file was saved etc. * Mac OS Snow Leopard has a similar feature called Spotlight or Sherlock in earlier versions * Instant search can also find e-mails; can also be used in Windows Explorer

Naming Files
Are there special rules I have to follow when I name files? * The first part of a file or file name is the name you assign to it before you save it * In a Windows application, an extension or file type follows the file name and a period (.) * It identifies what family of the files it belongs to, or which application is needed to read the file

Do I need to know the extension of a file to save it? * You do not need to add the extension to the file name, it is added by default * Office 2007 and 2010 has different file extensions than earlier versions * The new versions have an “x” at the end of the extension to represent XLM file format

Are there things I shouldn’t do when naming my files? * Each OS has its own naming conventions/rules * Make sure you name your files descriptively so they are easily identified

How can I tell where my files are saved? * You can designate where you want to save your file for easy reference * “Documents”, “music”, “downloads”, “videos”, etc. * You can determine the location of a file by its file path * This file path starts with the drive in which the file is located * This includes all folders, subfolders, the file name, and the extension * “Documents” is usually the primary folder * The backslash character is referred to as a path separator in Windows and DOS

Working with Files
How can I move and copy files? * Once you have located your file you can perform other management actions such as open, copy, move, rename, delete etc. * You open the file by double-clicking form its storage location * Based on the file extension, the OS determines what is needed to open the file * You can copy the file elsewhere using the copy command * A duplicate will be created and the original file remains in its original location * The move command moves the original file from its folder and places it elsewhere

Where do deleted files go? * Deleted files go to the Recycle Bin on the desktop * Files from the DVD drive, flash drive, external hard drives do not end up in the recycle bin

How do I permanently delete files from my system? * You can permanently delete files from the system by emptying the recyle bin

Utility Programs * The operating system is the single most essential piece of software in your computer * It coordinates all the system’s activities and provides a means by which other software applications and users can interact with the system * Utility programs are small applications that perform special functions * They are sometimes incorporated into the OS * E.g. Windows has its own firewall and file-compression utilities * Other utilities include antivirus and security programs which require frequent updating * Norton System Works are usually offered as freeware or shareware that can be downloaded * Basic utilities are designed to manage and rune the computer hardware in the OS * These utilities are usually found in the Control Panel or Start Menu

Display Utilities
How can I change the appearance of my desktop? * Personalization is found in the appearance and personalization on the control panel * You can right click anywhere on your desktop as well * It changes the appearance of your desktop by changing the background or the colour * You can customize your desktop and screensaver with your favourite images
The Programs and Feature Utility
What is the correct way to add new programs to the system? * When you install a new program, it automatically runs a wizard to set it up * If the wizard doesn’t start, you can go to the Programs and Features utility found in the programs folder in the Control Panel * It prompts the OS to look for the setup program

What is the correct way to remove unwanted programs from my system? * The best way to delete a program is NOT to remove it from the C drive * The best way is to uninstall the program file along with al its supporting files

File Compression Utilities
What is file compression? * A file compression utility is a program that takes our redundancies in a file to reduce the file size

How does file compression work? * It is helpful to make large files more compact and easier to send over the internet or upload * Most compression programs look for repeated patterns of letters and replace them with a shorter placeholder

How effective are file compression programs? * The effectiveness of the file compression depends on the type of size of the individual file and the compression method used * Current programs can reduce files by 50% * PDF files already contain compression of some sort so they don’t’ need to be compressed

How do I decompress a file I’ve compressed? * Decompressing a file is done when you want to restore the file to its original state so that the pieces of file that the compression process temporarily removed are restored to the document * Generally he programs used to compress the file has the capability to decompress it

System Maintenance Utilities
Are there any utilities that make my system work faster? * Disk cleanup is a utility that cleans or removes unnecessary files form your hard drive * This includes the build-up in your recycling bin and temporary files, which are created by Windows to store data temporarily when a program is running * Usually these files are deleted when you exit but sometimes it forgets * You can use disk cleanup by clicking the start button and selecting all programs, accessories folder, and then system tools to remove temporary internet files

How can I control which files Disk Cleanup deletes? * The program scans your hard drive to determine which folders have files that can be deleted and you can choose which files you want deleted

What else can I do if my system runs slowly? * As you add and delete information in a file, the pieces are all scattered and hard to locate * The windows disk defragmenter regroups related pieces of files on the hard drive which allows the OS to work more efficiently

How do I diagnose potential errors or damage on my storage devices? * Error-checking once known as ScanDisk is a utility that checks for lost files and fragments as well as physical errors on your hard drive * Lost files and fragments occur when you save, resave, move, delete, and copy files * When the system gets confused, it leaves references on the file allocation table (FAT) * Physical errors on the hard drive occur when the mechanism that reads the hard drive’s data can no longer determine whether the area holds a 1 or a 0 * These areas are called bad sectors * Sometimes error-checking can recover lost data but it usually deletes the files that are taking up space * Error-checking also makes note of the bad sectors so that the system won’t store data there next time

Where can I find Error-checking? * To locate error-checking, from the start menu, right click the disk you want to diagnose, select properties, and then tools

How can I check on a program that has stopped running? * Task Manager Utility has the ability to check a non-responsive program which can be bought up by using task manager from control panel or control + Alt + Delete * If outside assistance is required, Dr. Watson for Windows can father information about the computer when there is a program error
System Restore and Backup Utilities
Is there an undo command for the system? * System Restore lets you roll your system settings back to a specific date when everything was working properly * System Restore Point is a snapshot of your entire systems settings * System Restore does not affect your personal data files (MS Word) so changes to computer won’t affect file
How does the computer remember its previous settings? * Windows automatically creates a system restore point when you start your computer

How can I protect my data in the event something malfunctions in my system? * Backup and Restore Utility can create a duplicate copy of all the data on your hard drive and copy it to another storage device such as a DVD or external hard drive * Apple has Time Machine (Back Up Utility) * If you encounter a non-recoverable error on a Windows machine that System Restore cannot repair, you can recover Windows from a system repair disc
The Task Scheduler Utility
How can I remember to perform all these maintenance procedures? * Task scheduler utility allows you to schedule tasks to run automatically at predetermined times with no additional action necessary on your part

Accessibility Utilities
Are there utilities designed for users with special needs? * Microsoft windows includes an Ease of Access Centre, which is centralized location for assistive technology and tools to adjust accessibility settings * High contrast allows you to select a colour scheme in which you can control the contrast between text and background * Magnifier is a utility that creates a separate window that displays a magnified portion of the screen * Narrator is a basic speech program that reads what is on screen, whether it’s the contents of a window, menu options or text you have typed * On- Screen Keyboard displays a keyboard on the screen * Windows Speech Recognition is an effective tool that allows you to dictate text and control your computer by voice

Chapter 6: understanding and accessing hardware: evaluating your system
Is it the Computer or me? Moores Law: The number of transistors inside a computer increase so fast the CPU capacity will double every 18 months. Predicted to be accurate until 2020 when production methods will most likely change. In addition to the CPU becoming faster, other system components are also improving dramatically. For example, the capacity of memory chips such as DRAM—the most common form of memory found in PCs—increases about 60 percent every year. Hard drives have been growing in storage capacity by 50 percent each year.
What is Your Ideal Computer? Most students would probably want the most RAM and highest speed CPU possible. Gamers may be interested in a good quality flat panel monitor. Alternate storage is easily found in USB devices.
Choosing a desktop or notebook system Notebook computers are more expensive than similarly equipped desktops. Notebook computers are more easily stolen and are more difficult to upgrade. They are also prone to damage from being dropped. Desktop computers are easier to upgrade but difficult to ship if the system needs repair.
Accessing your hardware: evaluating your system To determine whether your computer system has the right hardware components to do what you want it to do, you need to conduct a system evaluation. (looking at your computer’s subsystems) 1) CPU
The CPU or processor is the "brains" of the computer. It processes instructions, performs calculations, manages the flow of information through a computer system, and is responsible for processing the data you input into information. The CPU is located on the motherboard. The CPU is composed of two Chapters: the control Chapter and the arithmetic logic Chapter (ALU). The control Chapter coordinates the activities of all the other computer components. The ALU is responsible for performing all the arithmetic calculations and makes logic and comparison decisions, such as comparing items to determine if one is greater than, less than, equal to, or not equal to another. Every time the CPU performs a program instruction, it goes through the same series of steps, called a machine cycle: First, it fetches the required piece of data or instruction from RAM. Next, it decodes the instruction into something the computer can understand. Once the CPU has decoded the instruction, it executes the instruction. It then stores the result to RAM before fetching the next instruction. The computer goes through these machine cycles at a steady and constant pace. This pace, known as clock speed, is controlled by the system clock, which works like a metronome in music. The system clock keeps a steady beat, regulating the speed at which the processor goes through machine cycles. Processors work incredibly fast, going through millions or billions of machine cycles each second. Processor speed is measured in Chapters of MHz and GHz. Hertz here means "machine cycles per second," so a 3.0-GHz processor performs work at a rate of 3 billion machine cycles per second.
In addition to pure processing speed, CPU performance also is affected by the speed of the front side bus (or FSB) and the amount of cache memory. The FSB connects the processor (CPU) in your computer to the system memory. The faster the FSB is, the faster you can get data to your processor. FSB speed is measured in Megahertz (MHz). Cache memory is another important consideration that determines CPU performance. Cache memory is a form of random access memory but is more accessible to the CPU than regular RAM. Because of its ready access to the CPU, Cache memory is even faster than RAM to get data to the CPU for processing.
Replacement CPUs are expensive. In addition, although it is reasonably easy to install a CPU, it can be difficult to determine which CPU to install. Not all CPUs are interchangeable, and the replacement CPU must be compatible with the motherboard. Some CPUs are optimized to process multimedia instructions and can handle audio and video processing commands much more quickly than other processors. Intel CPUs called core duo processors work on two separate sets of instructions at the same time, in parallel. Use less power than having two CPUs running at once and deliver a substantial increase in performance.

2) RAM
Random access memory (RAM) is your computer's temporary storage space. Although we refer to RAM as a form of storage, RAM is really the computer's short-term memory. As such, it remembers everything that the computer needs to process the data into information, such as inputted data and software instructions, but only while the computer is on. This means that RAM is an example of volatile storage. When the power is off, the data stored in RAM is cleared out. This is why, in addition to RAM, systems always include nonvolatile storage devices for permanent storage of instructions and data when the computer is powered off. Hard disks provide the greatest nonvolatile storage capacity in the computer system. Memory modules (or memory cards), the small circuit boards that hold a series of RAM chips, fit into special slots on the motherboard. Most memory modules in today's systems are called dual inline memory modules (DIMMs). Several different types of RAM are available. In current systems, the RAM memory used most often comes in the form of DDR or DDR2 memory modules, but in older systems, other types of RAM may have been used. RAM has a significant impact on the overall performance of your computer. The amount of RAM that is actually sitting on memory modules in your computer is your computer's physical memory. The memory that your operating system uses is referred to as kernel memory. To determine how much RAM is needed you must look at the memory requirements of each program and add them up.

3) Storage subsystem (hard drive and other drives)
Of all the nonvolatile storage devices, the hard disk drive (or just hard drive) is used the most. With storage capacities of up to 1.5 Terabytes (TB), hard disk drives have the largest storage capacity of any storage device. The hard drive's access time, or the time it takes a storage device to locate its stored data and make it available for processing, is also the fastest of all permanent storage devices. Hard drive access times are measured in milliseconds, or thousandths of seconds. Another reason hard drives are popular is that they transfer data to other computer components (such as RAM) much faster than the other storage devices do. This speed of transfer is referred to as data transfer rate and is expressed in either megabits or megabytes per second.
There are several ways in which you can increase your storage capacity or add extra drives to your computer. If your hard drive is running out of space, you can replace the one installed in your system Chapter with a bigger one or you can install an additional hard drive in your current system if you have an extra drive bay. You might also chose to use an external hard drive you can plug into a USB or FireWire port. If your computer didn't come with an internal CD-RW or DVD-RW drive, and if you have an open drive bay, you can install a drive there. If you don't have open bays in your system, you can add external CD/DVD drives that you attach to your computer through an open port. Although most desktop computers don't include internal flash memory card readers, you can purchase external memory card readers that connect to your system through an open USB port. You can also use flash drives, which plug directly into a USB port.

4) Video Subsystem (video card and monitor)
How video is displayed depends on two components: your video card and your monitor. It's important that your system have the correct monitor and video card to meet your needs. If you use your computer system to display files that have complex graphics, such as videos on DVD or from your camcorder, or even play graphics-rich games with a lot of fast action, you may want to consider upgrading your video subsystem. 5) Audio subsystem (sound card and speakers)
The audio subsystem consists of speakers and a sound card. Two types of speakers ship with most personal computers: amplified speakers (which use external power) or unamplified speakers (which use internal power). Amplified speakers generally produce better quality sound. However, they usually do not adequately reproduce the bass sounds that make gaming and musical scores sound richer and fuller. For better bass sounds, buy a speaker system that includes a subwoofer.
Sound cards attach to the motherboard and enable your computer to produce sounds. Most computers ship with a basic sound card, most of which are 3D sound cards. 3D sound is better at convincing the human ear that sound is omnidirectional, meaning you can't tell from which direction the sound is coming. This tends to produce a fuller, richer sound than stereo sound. To set up surround sound on your computer, you need two things: a set of surround-sound speakers and a sound card that is Dolby 7.1 compatible. Dolby 6.1 and 5.1 are also still on the market and have six speakers plus subwoofer or five speakers plus subwoofer, respectively.

6) Computer ports
A port is an interface through which peripheral devices are connected to your computer. Each type of port operates at a certain speed, measured in either kilobits per second (Kbps) or megabits per second (Mbps). To evaluate your system's port connectivity, check the devices you'd like to be able to connect to your computer and look for what type of port they require. Does your system have the ports necessary to connect to all of these devices? This chapter will discuss different type of ports and how to add ports. Please read class notes and text book for detail.
Making the Final Decision When a decision is required, you have to ask yourself how you use your computer system. How might you use it if it were more capable? Can your existing system do what you want it to? If not, can you purchase the parts and install them to meet the capability? Then, if you add up the cost of the parts, figure in the value of headaches and labor required to install those parts, and compare the total to the cost of a new machine that will do the same tasks and more, you arrive at a point where the decision should be easy.

Chapter 7: Networking (connecting computing devices)

Networking Fundamentals
What is a computer network? * A computer network is simply two or more computers that are connected via software and hardware so that they can communicate with each other * ATM, get gasoline, or using the internet are examples of interacting with a network * Each device that is connected to a network is referred to as a node. * A node can be a computer, a peripheral, a game console, a digital video recorder, or a communication device * Main function for most networks is to facilitate information sharing
What are the benefits of networks? * A network allows you to share the high-speed internet connection coming into your home * Allows you to share peripheral devices, such as printers * You can have multiple computers printing from one wireless printer
Besides peripheral and internet connections, does networking facilitate any other types of resource sharing? * Easily share files between networked computers without having to use portable storage devices such as flash drives to transfer the files * In addition, you can set sharing options in Windows or OS X that allow the user of each computer on the network to access files (such as music or videos) stored on any other computer on the network
Are there disadvantages to setting up a network? * Networks involves the purchase of additional equipment to set them up, so cost is disadvantage * Networks need to be administered, at least to some degree * Network administration involves task such as installing new computers and devices, monitoring the network to ensure it is performing efficiently, updating and installing new software on the network and configuring or setting up, proper security for a network
Network Architectures * Network architectures refers to the design of a network * Network architectures are classified according to the way in which they are controlled and the distance between their node
Describing Networks Based on Network Administration
What are different types of control do I have over my network? * A network can be administered or managed in 2 main ways, locally or centrally * Local administration means that the configuration and maintenance of the network must be performed on each individual computer attached to the network * Example of local is peer-to-peer network * Central administration means that tasks can be performed from one computer and affect the other computers on the same network * Example of central is a client/server network
What is a peer-to-peer network? * In a peer-to-peer (P2P) network each node connected to the network can communicate directly with every other node on the network * All nodes on this type of network are peers (equals) * When printing, for example, a computer on a P2P network doesn’t have to go through the computer that’s connected to the printer. Instead it can communicate directly with the printer
What are client/server networks? * A client/server network contains two different types of computer: clients and servers. * A client is a computer on which users accomplish specific tasks (such as construct spreadsheets) and make specific requests (such as printing a file) * The server is the computer that provides information or resources to the client computers on the network * The server on a client/server network also provides central administration for network functions such as printing * Internet is an example of a client/server network
Are client/server networks ever used as home networks? * Although client/server networks can be configured for home use, P2P networks are more often used in home because they cost less than client/server networks and are easier to configure and maintain * A home network server is designed to store media, share media and back up files on computers connected to the network * All computers connected to the network can access the server
Describing Networks Based on Distance
How does the distance between nodes define a network? * The distance between nodes on a network is another way to describe a network * A local area network (LAN) is a network in which the nodes are located within small geographic area * Example include a network in a computer lab at school or at a fast-food restaurant * A home area network (HAN) is a network located in a home * HANs are used to connect all of a home’s digital devices, such as computers peripherals, phones, gaming devices, digital video recorders and televisions
Is it possible to connect LANs? * A wide area network (WAN) is made up of LANs connected over long distances * Two or more LANs connected form a WAN
Are wireless networks that cover large areas like cities considered WANs? * Networks designed to provide access to a specific geographic area, such as an entire city is usually called a Metropolitan area network (MAN)
Network Components * To function, all networks must include * 1. A means of connecting the nodes on the network (cables or wireless technology) * 2. Special devices that allow the nodes to communicate with each other and to send data * 3. And software that allows the networks to run
Transmission Media
How are nodes on a network connected? * All network nodes are connected to each other and to the network by transmission media * Transmission media establishes a communication channel between the nodes on a network and can either be wireless or wired * Wireless networks use radio waves to connect nodes * Wired networks use various types of cables (wires) to connect nodes * Twisted-pair cable is made up of copper wires that are twisted around each other and surrounded by a plastic jacket * Normal telephone cable is a type of twisted-pair cable, * Coaxial cable consists of a single copper wire surrounded by layers of plastic (example TV cable is a coaxial cable) * Fiber-optic cable is made up of plastic or glass fibers that transmit data at extremely fast speed
Does it matter what type of media you use to transfer data? * The media you choose depends on the requirements of a network’s user * Different types of transmission media transmit data at different speeds * Data transfer rate (also called bandwidth) is the maximum speed at which data can be transmitted between two nodes on a network * Throughput is the actual speed of data transfer that is achieved * Throughput is always less than or equal to the data transfer rate * Data transfer rate and throughput are usually measured in megabits per second
How do the different nodes on the network communicate? * Network adapters are devices connected to or installed in network nodes that enable the nodes to communicate with each other and to access the network * all desktop and notebook computers sold today contain network adapters installed inside the device * this type of adapter is referred to as a network interface card (NIC) * NIC allows you to connect to wireless networks
Why would I ever consider using wired connection with my notebook computer? * Wired connections can sometimes provide greater throughput than current high speed wireless networks * Wireless signals are more susceptible to interference from magnetic and electrical sources * Other wireless networks can interfere with the signals on your network * Certain building materials and metal can decrease throughput * Throughput varies depending on the distance from your networking equipment
Network Navigation Devices
How is data sent through a network? * Network navigation devices facilitate and control the flow of data through a network * Data is sent over transmission media in bundles * Each bundle is called a packet
What network navigation devices will I use on my home network? * The two most common navigation devices are routers and switches * A router transfers packets of data between two or more networks * A switch is a “traffic cop” on a network * Switches receive data packets and send them to their intended nodes on the same network
Network Software
Is the same software used in client/server networks? * Client/server networks are controlled by centralized servers that have specialized network operating system (NOS) software installed on them * This software handles requests for information, internet access, and the uses of peripherals for the rest of the network nodes
Ethernet Home Networks
What type of peer-to-peer network should I install in my home? * The vast majority of home networks are Ethernet networks * An Ethernet network is so named because it uses the Ethernet protocol as the means by which the nodes on the network communicate * The Ethernet protocol makes Ethernet networks extremely efficient at moving data * Ethernet networks use both wireless and wired transmission media
What is the current wireless standard for Ethernet networks? * The current standard Ethernet networks is the 802.11n standard (also called WiFi), which was ratified in 2009 * Four standards are currently defined under 802.11 WiFi standard: 802.11a, 802.11b, 802.11g and 802.11n * 802.11n is the fastest data transfer rate and thus most desirable choice for home networks * Backward compatibility is the accommodation of current devices being able to use previously issued standards in addition to the current standards
How do 802.11n wireless devices work? * Wireless routers and network adapters contain transceivers * A transceiver is a device that translates the electronic data that needs to be sent along the network into radio waves and then broadcasts these radio waves to other network nodes * Transceivers serve a dual function because they also receive the signals from other network nodes * Devices using wireless standards developed prior to the 802.11n standard only utilized one antenna for transmitting and receiving data * Devices that use multiple input multiple output (MIMO) technology are designed to use multiple antennas for transmitting and receiving data
Throughput Speeds
What kind of throughput is achievable with wired networks connections? * Up to one gigabit per second of throughput is possible using gigabit Ethernet standard, which is the most commonly used wired Ethernet standard deployed in devices designed for home networks
What type of cable do I need to connect to a wired Ethernet network? * The most popular transmission media option for wired Ethernet networks is unshielded twisted-pair (UTP) cable. * UTP cable is composed of four pairs of wires that are twisted around each other to reduce electrical interference
Do all wired Ethernet networks use the same kind of UTP cable? * Three main types, Cat 5E, Cat 6, Cat6a * Cat 6 cable is designed to achieve data transfer rates that support a gigabit Ethernet network
Connecting devices to routers
How many computers and other devices can be connected to a router in a home network? * Most home wireless routers can support up to 253 wireless connections at the same time * This number is the theoretical maximum
Are wireless routers for Windows and OS X networks different? * All routers that support the 802.11n standard should work with computers running windows or OS X * However, apple has designed routers that are optimized for working with apple computers
Network-Ready devices
What is a network-ready device? * A network-ready device (or internet ready) can be connected directly to a router instead of a computer on the network * Network ready devices usually contain wireless and/ or wired network adapters inside them
What can I attach to my network to facilitate file sharing and back up of data? * Network attached storage (NAS) devices are specialized computing devices designed to store and manage your data
Specialized home network devices
What is I don’t need the full function ality of a PC, but I still want to access internet content? * The launch of the apple ipad signaled a resurgence of internet appliances * The main function of an internet appliance is easy access to the internet, social networking sites, e-mail, video, news and entertainment
Securing wireless networks * All computers that connect to the internet need to be secured by using a firewall, which is a hardware or software solution that helps shield your network from prying eyes
Why is a wireless network more vulnerable than a wired network? * With a wired network, it is fairly easy to tell if a hacker is using your network * However, wireless networks have a wide range that may extend outside of your house
Why should I be worried about someone logging onto my wireless network without my permission? * Because of piggybacking, which is connecting to a wireless network (other than your own) without the permission of the owner * This is illegal
How is my wireless network vulnerable? * 7 ways to secure your network * 1. Change your network name (SSID) * each wireless network has its own name to identify it, which is known as the server set identifier or SSID * 2. Disable SSID broadcast * Most routers are set up to broadcast their SSIDs so that other wireless devices can find them, turning it off makes it more difficult for a hacker to detect your network * 3. Change the default password on your router * Hackers know the default password of most routers, and if they can access your router, they can probably break into your network * 4. Turn on security protocols * Most routers ship with security protocols such as wired equivalent privacy (WEP) or WiFi protected access (WPA), both used encryption to protect data in your wireless transmission * 5. Implement media access control * Each network adapter on your network has a unique number assigned to it by the manufacturer, this is called a media access control (MAC) address, and it is a number printed right on the network adapter * 6. Limit your signal range * Many routers allow you to adjust the transmitting power to low, medium, or high, cutting down the power to low or medium could prevent your signal from reaching too far away from your home * 7. Apply firmware upgrades * Your router has read-only memory that has software written to it * This software is known as firmware * As bugs are found in the firmware, manufacturers issue patches, just as the markers of operating system softwardo
Configuring software for your home network * Once you install the hardware for your network you need to configure your operating system software for networking on your computers
Troubleshooting network problems
What if a node on the network can’t get adequate throughput? * A wireless range extender is a device that amplifies your wireless signal to get it out to part of your home that are experiencing poor connectivity

Chapter 8 summary
Digital lifestyle * Any type of information can be digitized * Analog waves/continuous waves: sound and light waves * Illustrate loudness of a sound or brightness of colours in an image * Digital formats describe signals as long strings of numbers vs. analog formats are sound and light waves

Advantages of Digital over Analog * Digital information can be reproduced exactly and distributed easily
Analog vs. Digital Entertainment | Analog | Digital | * Music | * Vinyl Record albums * Cassette Tapes | * CDs * MP3 files | * Photography | * 35-mm single lens reflex (SLR Cameras) * Photos stored on film | * Digital cameras, digital SLRs * Photos stored as digital files | * Video | * 8-mm, Hi8 and VHS camcorders * Film stored on VHS tapes | * Digital video cameras * Film stored as digital files; often distributed on DVD blue ray disks | * Radio | * AM/FM radio | * HD Radio * Sirius/XM radio | * Television | * Conventional broadcast analog tv | * Digital television (DTV) |

Digital Telephony
Telephony: use of equipment to provide voice communication over a distance
Cell Phones * Shifted to digital * Analog-digital converter chip: converts voice sound waves into digital signals * Digital signal processor: used to compress digital data into small possible space so it will be transmitted quickly to other phone * Base transceiver station: large communications tower with antennas, amplifers, recievers, transmitters * Processor coordinates sending all data among other electronic components inside phone * Runs cellphones operating system * Popular processors: Samsung SC, the Texas Instruments OMAP, Marvel Xscale processor

Memory * Information saved in cell phones needs to be stored in memory * Operating system stored in read-only memory (ROM) * 2 kinds of memory used in computers: volatile( requires power to save data), and non-volatile(stores data even when you turn off your phone)

Input/output devices * Primary input devices for cellphones are microphone and keypad
Transferring Music from computer to Cellphone * Some phones use flash cards that can be easily removed * Almost all phones designed with USB port

Synchronizing cellphone and Computer * Updating data so that files on your cellphone and computer are the same * Place cell phone in cradle or connect to USB port and click sync

Transferring files wirelessly * Bluetooth technology uses radio waves to transmit data signals over short distances

Text Messaging * Short message service (SMS) allows you to send short messages over mobile networks * Uses cell phone network to transmit messages * When sending an SMS an SMS calling centre receives the message and delivers it to the appropriate mobile device using store-and-forward technology * Can be cheaper then phone calls * Text prediction algorithm: typing a single letter pulls up a list of popular words beginning with that letter

Multimedia message service (MMS) allows you to send messages that include text, sound, images, video clips to other phones or emails

Speed of digital information to cellphones * Often slower than home phones * Providers have introduced many cellphone based on two standards that support faster data transfer technologies: EDGE (enhanced data rate for global evolution) and 3G * Brought much faster data transfer- 1.7 Mbps under ideal conditions * If in rage of WiFi it is a faster option but 3G and EDGE are used to blanket major urban areas with connectivity, whereas you may need to search for a WiFi hotspot *

Internet Display on Cellphones * Microbrowser software: provides a web browser that is optimized to display web content effectively on the smaller screen * More and more websites being created with content specifically designed for wireless devices * Specifically designed content- text based and contains no graphics is written in a format called Wireless Markup Language (WML)

VoIP * Voice over internet protocol * Turns a standard internet connection into a means to place phone calls, including long-distance calls * Traditional telephone communications use analog voice data and telephone connection vs. VoIP which uses technology similar to e-mail to send voice data digitally over internet * Need: speakers, microphone, internet connection and VoIP provider * Ex. Skype

Advantages and Disadvantages of VoIP * Advantages: free or low cost, portability(all you need is internet connection) * Disadvantages: sound quality and reliability, loss of service if power is interrupted, security risks
New Features * Telephone messages automatically bundled as e-mails and sent to account * Caller can be displayed on television

Cellphone Security * Viruses can effect cell phones * Potential of cellphone viruses ranges from mildly annoying(certain features of phones stop working) to the expensive (your phone is used without your knowledge to make expensive calls) * Symantec, McAfee, and F-secure are the leading companies currently providing antivirus software for mobile phones * Do not download ringtones, games or other software from unfamiliar websites

Digital Media * All digital media created with digitized information

1. Playing music creates analog waves 2. Microphone feeds sound waves into a chip called an analog to digital converter (ADC) inside recording device 3. ADC digitizes waves into a series of numbers 4. Series of numbers can be recorded onto CD’s and DVD’s or sent electronically 5. On the receiving end, a playback device (CD/DVD player) fed the same series of numbers. Inside playback device is a digital-to-analog converter (DAC) a chip that converts the digital numbers to a continuous wave 6. Analog wave tells receiver how to move the speaker cones to reproduce original waves, resulting in same sound as original

* Digital wave will be close to exact * How accurate or how close the digitized wave is in shape to the original analog wave depends on sampling rate of ADC * Sampling rate: specifies number of times analog wave is measured each second * Higher the sampling rate= more accurately the original wave can be recreated * Higher sampling rates also produce more data and result in bigger files * When sounds or image waves are digitized it means analog data is changed into digital data- from a wave to a series of numbers

Digital Music
Portable media players (PMPs) are small portable devices(ipod) that enable you to carry your MP3 files around with you * Letters at the end of a file name indicate how data in the file is organized (MP3, AAC, WMA) * Video formats- DivX, MPEG-4, WMV, XviD * Number of electronic devices now incorporate capability to carry electronic files and play music and video files * Number of songs or hours of video a portable media player can hold depends on how much storage space it has * Most have built in flash memory- a type of non-volatile memory to store files * Controlling the size of an mp3 file: if you are converting a song from a cd into digital MP3 file you can select sampling rate yourself * Decide by considering what quality sound you want/ how many song you want to fit onto your MP3 player * Some PMP’s allow you to add memory by inserting removable flash memory cards * Flash memory is non-volatile, can be erased and rewritten with new data * Transfer media files to PMP: they use internal hard drives to store information—use a high speed port such as USB 2.0, FireWire ports *
GPS
* Global positioning system * Computes your location anywhere on earth from a system of orbiting satellites

Digital Photography
Analog photography- 35-mm single- lens reflex (SLR) camera * A shutter opens creating an aperture(small window in camera) that allows light to hit the 35-mm film inside * Chemicals coating the film react when exposed to light * Additional chemicals develop the image on the film- image is printed on special light-sensitive paper * Variety of lenses and processing techniques, special equipment, filters needed
Digital Photography * Do not use film- capture images on electronic sensors called charge- coupled device arrays(CCD) and convert those images to digital data(long series of numbers that represent the color and brightness of millions of points in image) * Allows u to see images instant you took them * Most camera models can record digital video as well * Digital SLR camera allow you to switch among different lenses and important features to photographers * Larger, heavier, use more battery power * Image quality- resolution: number of data points it records for each image captured * Resolution measured in megapixels (MP) mega- short for millions- pixel short for picture element * Point and click cameras usually offer resolutions from 8MP to 15MP * Professional digital SLR cameras 21.1 MP- sell for thousands of dollars * Lower resolution fine for smaller pictures (5” x 7”) * File formats: flash memory card- digital cameras allow you to choose from several different file types in order to compress image data into less memory space * Most common file types supported by digital cameras are uncompressed data (RAW) and Joint Photographic Experts Group (JPEG) * Raw files have diff formats and extensions depending on manufacturer * Raw files records all of original info so it is larger than compressed JPEG file * Transferring files to computer- many prints can be directly from our camera or flash memory card on a photo printer * Digital cameras have built in USB 2.0 port * Can connect camera to computer and copy converted images as uncompressed files or in compressed format as JPEG files * OR transfer flash card from camera to built in memory card reader on computer * Some cameras support wireless connection * Panasonic Lumix TZ50 uses integrated WiFi to connect to Google’s online photo service, Picasa, and uploads images to a Picasa Web photo album automatically * Making old photos digital: digital scanners convert paper text and images into digital formats * Any flat material on glass surface of scanner and convert it to a digital file * Most scanner software allows you to store converted images as RAW files or in compressed form as JPEG files * Scanner quality measured by resolution- given in dots per inch (dpi) * Most modern scanners can digitize a document at resolutions as high as 4,800 x 9,600 dpi in color or greyscale mode * You can easily connect scanner to computer using USB 20 or FireWire Ports * Typically come with software that supports optical character recognition(OCR) * OCR converts pages of handwritten/typed text into electronic files * You can open and edit these converted documents with traditional word processing programs (Microsoft Word) * Printing Digital Images: Professional service or your own printer * Online services (Flickr, shutterfly) sore images and allow you to organize them into photo albums or create hard copy prints, mugs, t-shirts, calenders * Photo printers for home: two technologies- inkjet and dye sublimation * Most popular and inexpensive- inkjet * Some are capable of printing high quality colour photos but vary in speed and quality * Dye sublimation printers produce images using heating element * Heating element passes over ribbon of translucent film that has been dyed with bands of colours * Depending on temperature of element dyes are vaporized from solid to gas * Gas vapors penetrate photo paper before they cool and return to solid form producing glossy, high quality images

Digital Video * Comes from several sources * Now often people create own digital videos * Digital camcorders, cell phones, digital cameras, webcams work to create digital video * Television broadcasted in digitally formatted signals * Internet delivers huge amount of digital video through Google Video, YouTube, Vimeo, webcasting sites like Ustream * Pay services: itunes, Netflix, Amazon’s Video On Demand download service * Recording your own digital video: video equipment for home use sores info in digital video (DV) format * Do not require any tapes, store hours of video on built-in hard drives or flash cards * Easily transfer video files to computer and using video editing software edit the video * Video editing software allows you to manipulate video file, add titles, animations, audio, backround music, sound effects, additional information * Popular video file formats: Quicktime, Moving Picture Experts Group( MPEG), Windows Media Video, Microsoft Video for Windows, RealMedia, Adobe Flash Video * Choice of file format depends on what you want to do with video * DVD menuing system: use special DVD authoring software such as Pinnacle Studio or Adobe Encore DVD * Quickest way to get video out to viewers is the web-YouTube * As of June 13 2009 all television stations were required to make the move to digital signal broadcasting
HD vs. Digital * HD= high definition * Guratees specific resolution and specific aspect ratio * Typical HD set has atleast 3 HDMI connectors allowing game consoles, Blu-ray players, cable boxes to be connected and produce highest quality output * HDMI is a single cable with 1 plug that carries all video and audio information * Many have built in SD reader- allows users to display slide shows * PC VGA port is included in most sets- allows you to feed computers output video signal directly to television so you can display an internet browser or work on big screen * Advantages to digital video: can be paused, rewound in real time, other information services can be integrated with broadcast, so telephone number could appear on screen if call came through

Digital Mobility and Access * Selecting the right device for needs: netbook runs a fully featured operating system but weighs in at 2lbs or less * Internet Tablet- very light portable vevce * Cellphone, PMP, Smartphone, Internet Tablet, Netbook, Tablet PC, Notebook- serveral different mobile devices to choose from

Ubiquitous Computing- concept that computing will be wove into the fabric of everyday life until it is indistinguishable from it

Chapter 9: Securing Your System

Keeping Your Data Safe * Cybercrimes are criminal acts conducted by cybercriminals through the use of computers * Cybercriminals are individuals who use computers, networks and the internet to perpetrate crime * Computer users need to protect themselves from becoming victims of cybercriminals * The Internet Crime Complaint Centre (IC3) processed more than 275,000 complaints related to internet crime in 2008 * The majority of complaints (more than 58%) were related to three key areas: Internet auction fraud, non-delivery of merchandise or failure to pay * Much of the credit card fraud is perpetrated when credit card numbers are stolen by phishing (tricking people into revealing information) or by virus programs that gather credit card data * Non-fraud-related complaints pertained to issues such as computer intrusions, unsolicited e-mail, and child pornography * Creating and disseminating computer viruses is one of the most widespread types of cybercrimes

Computer Threats: Viruses * A computer virus is a computer program that attaches itself to another computer program (known as the host program) and attempts to spread to other computers when files are exchanged * Viruses normally attempt to hide within the code of a host program to avoid detection * Viruses, by definition, have a method to spread themselves * Virus creation and deployment is a form of cybercrime * A computer virus’s main purpose is to replicate itself and copy its code into as many other files as possible * Although virus replication can slow down networks, it is not usually the main threat * The majority of viruses have secondary objectives or side effects, ranging from displaying annoying messages on the computer screen to destroying files or the contents of entire hard drives * If the computer is exposed to a file infected with a virus, the virus will try to copy itself and infect a file on your computer * Shared disks or flash drives are common sources of virus infection, as is e-mail * Downloading or running a file attached to an e-mail is how a computer becomes effected * Types of viruses: * Boot-Sector Viruses * A boot-sector virus replicates itself into a hard drive’s master boot record * The master boot record is a program that executes whenever a computer boots up, ensuring that the virus will be loaded into memory immediately, before anti-viruses can load * Logic Bombs and Time Bombs * A logic bomb is a virus that is triggered when certain logical conditions are met * A time bomb is a virus that is triggered by the passage of time or on a certain date * Worms * A worm is slightly different from a virus in that a worm attempts to travel between systems through network connections to spread an infection * Script and Macro Viruses * A script is a series of commands (a mini-program) that is executed without your knowledge * A macro virus is a virus that attaches itself to a document * E-mail viruses use the address book in the victim’s email system to distribute the virus * Encryption Viruses * When encryption viruses infect your computer, they run a program that searches for common types of data files and compresses them using a complex encryption key that renders your files unusable * Types of virus classifications: * A polymorphic virus changes its own code to avoid detection * A multipartite virus is designed to infect multiple file types in an effort to fool the antivirus software that is looking for it * Stealth viruses temporarily erase their code from the files where they reside and then hide in the active memory of the computer

Computer Safeguard: Antivirus Software * Antivirus software is software specifically designed to detect viruses and protect computers and files from harm * Although antivirus software is designed to detect suspicious activity on your computer at all times, you should run an active virus can on your entire system at least once a week * Most antivirus software looks for virus signatures in files – a virus signature are portions of the virus code that are unique to that particular computer virus * Antivirus software scans files when they’re opened or executed * If it detects a virus signature or suspicious activity, it stops the execution of the file and notifies you it has detected a virus; usually it gives you the choice of deleting or repairing the infected file and places the virus in a secure area – this is called quarantining * Through inoculation, the antivirus software records key attributes about files on your computer and keeps these statistics in a safe place on your hard drive * Antivirus software catches known viruses effectively; thus your computer can still be attacked by a virus that your antivirus software does not recognize – to minimize this risk, keeping your antivirus software up to date is key * Other ways to protect your system are: * Keeping your computer’s antivirus and operating system (OS) software up to date * Loading security patches as soon as they are available * Enabling automatic updates for both the OS and all other software loaded on your computer * To keep your instant messaging sessions safe, follow these precautions: 1. Allow contact only from users on your buddy or friends list 2. Never automatically accept transfers of data 3. Avoid using instant messaging programs on public computers * Malicious websites can be set up to attack your computer by downloading harmful software onto your computer. According to research conducted by Google, an attack known as a drive-by download, is common and affects almost 1 in 1000 web pages * Although many people decide to receive updates automatically, there are several options you can choose from in Windows. The following options are noteworthy: * Option 1: Install updates automatically * Option 2: Download updates but let me choose whether to install them * Option 3: Check for updates but let me choose whether to download and install them * Option 4: Give me recommended updates * Option 5: Microsoft update

Computer Threats: Hackers * A hacker is defined as anyone who unlawfully breaks into a computer system, whether it's an individual computer or a network * A hacker who breaks into systems just for the challenge of it may refer to himself/herself as a white-hat hacker – they tout themselves as experts who are performing a needed service for society by helping companies realize the vulnerabilities that exist in their systems * White hat hackers call hackers who use their knowledge to destroy information or for illegal gain black hat hackers * Amateur hackers are referred to as script kiddies – script kiddies don’t create the programs they use to hack into computer systems; instead, they use tools created by skilled hackers * If you perform financial transactions online, credit card and bank account information can reside on your hard drive and may be detectable by a hacker * Even if this data is not stored on your computer, a hacker might be able to capture it when you’re online by using a packet sniffer * Data travels through the internet in small pieces, each called a packet * A packet sniffer is a program that looks at each packet as it travels on the internet – not just those that are addressed to a particular computer, but all packets * Some packet sniffers are configured to capture all the packets into memory, whereas others capture only those packets that contain specific content * Once a hacker has access to credit card information, he/she can either use it to purchase items illegally or sell the information to someone who will * If hackers can gather enough information in conjunction with your credit card info, they may be able to commit identity theft * Identify theft is characterized by someone using personal information about you to assume your identity for the purpose of defrauding others * A Trojan horse is a program that appears to be something useful or desirable, but something malicious runs in the background without your knowledge * Often, the malicious activity perpetrated by a Trojan horse program is the installation of a backdoor program that allows hackers to take almost complete control of your computer without your knowledge * A computer that a hacker controls in this manner is referred to as a zombie * In a denial-of-service (DoS) attack, legitimate users are denied access to a computer system because a hacker is repeatedly making requests of that computer system through a computer he/she has taken over as a zombie * Launching a DoS attack on a computer system from a single computer is easy to trace * Most savvy hackers use a distributed denial-of-service (DDoS) attack, which launches DoS attacks from more than one zombie at the same time * A botnet is a large group of software programs (called robots or bots) that runs autonomously on zombie computers * Logical ports are virtual communications gateways or paths that allow a computer to organize requests for information from other networks or computers

Restricting Access to Your Digital Assets * A firewall is a program or hardware device designed to protect computers from hackers * A firewall specifically designed for home networks is called a personal firewall * By using a firewall, you can close off open logical ports to invaders and potentially make your computer invisible to other computers on the internet * Most current operating systems include reliable firewalls; many security suites such as Norton, McAfee, ZoneAlarm, etc include firewall software * Bluetooth is a transmission medum for exchanging data wirelessly over short distances * If you have a Bluetooth-enabled device, you are susceptible to two severe types of mischief: Bluesnarfing and bluebugging * Bluesnarfing involves exploting a flaw in the Bluetooth access software for the purpose of accessing a Bluetooth device and stealing the information contained on it * Bluebugging presents more serious dangers – the process involves a hacker actually taking control of a Bluetooth-enabled device * Most devices with Bluetooth capability give you the option of making your device invisible to unauthorized Bluetooth devices * Passwords, used in conjunction with login Ids, are the major way we restrict access to computers, networks and online accounts * To create strong passwords, follow the basic guidelines: * The password should contain at least 14 characters and include numbers, cymbols and upper- and lowercase letters * The password should not be a single word or any word found in the dictionary * It should be a combination of several words with strategically placed uppercase letters * The password should not be easily associated with you * Use a different password for each system or website you need to access * Never tell anyone your password or write it down where others might see * Change your password on a regular basis * There are two types of users in Windows: Administrators and standard users * Setting up a password on a standard user account prevents other standard users from being able to access that user’s files * However, with administrator privileges, they can still see your files if you are a standard user

Managing Online Annoyances * If you use shared computers in such public places as libraries, coffee shops and college student unions, you should be concerned about a subsequent user of the computer spying on your surfing habits * You also never know what nefarious tools have been installed by hackers on a public computer * Many newer web browsers include privacy tools that help you surf the internet anonymously * There are portable privacy devices that help to protect your privacy when working on computers away from your home or office – simply plug the device into an available USB port on the machine and all sensitive internet files such as cookies, history and browser caches will be stored on the privacy device and not on the computer that you’re using * This significantly reduces the chance that your flash drive will become infected by any malware running on the public computer * You also avoid reading and writing to the hard disk, thus avoiding the possibility of leaving traces of your activity behind * Malware is software that has malicious intent * There are three primary forms of malware: Adware, spyware and viruses * Adware and spyware are not physically destructive like viruses and worms, which can destroy data * Known as grayware, they are the most intrusive, annoying or objectionable online programs that are downloaded to your computer when you install or use other online content * Adware is software that displays sponsored advertisements in a section of your browser window or as a pop-up ad box * Spyware is an unwanted piggyback program that usually downloads with other software you want to install from the internet * One type of spyware program known as a keystroke logger monitors keystrokes with the intent of stealing passwords, login Ids, or credit card information * Spam is unwanted or junk e-mail * A spam filter is an option you can select in your e-mail account that places known or suspected spam messages into a folder other than your inbox * There are several ways you can prevent spam: 1. Before registering on a website, read its privacy policy to see how it uses your e-mail address. Don’t give the site permission to pass on your e-mail address to third parties 2. Don’t reply to spam to remove yourself from the spam list. By replying, you are confirming that your e-mail address is active 3. Subscribe to an e-mail forwarding service. These services screen your e-mail messages, forwarding only those messages you designate as being okay to accept * Cookies (also known as tracking cookies) are small text files that some websites automatically store on your computer’s hard drive when you visit them * Cookies can provide websites with information about your browsing habits * Cookies do not go through your hard drive in search of personal information * Some sites sell the personal information their cookies collect to web advertisers who build huge databases of consumer preferences and habits * Because cookies pose no security threat, take up little room on your hard drive and offer you small conveniences on return visits to websites, there is no great reason to delete them

Protecting Yourself... from Yourself! * Information such as your social security number, phone number and street address are three key pieces of information that identity thieves need to steal an identity * The data on your computer faces three major threats: Unauthorized access, tampering and destruction * Backups are copies of files that you can use to replace the originals if they are lost or damaged * To be completely secure, backups must be stored away from where your computer is located * Removable storage media such as external hard drives, DVDs and flash drives have been popular choices for backing up files because they hold a lot of data and can be transported easily * There are two types of files that need backups: Program files and data files * A program file is used to install software and usually comes on CDs or DVDs or is downloaded from the web * A data file is a file that you have created or purchased – this includes research papers, spreadsheets, music files, movies, contact lists, etc. * An incremental backup (or partial backup) involves backing up only files that have changed or been created since the last backup was performed * An image backup (or system backup) means that all system, application and datafiles are backed up, not just the files that changed * Backing up files should be done frequently * There are three main places to backup files: 1. Online sites 2. Local drives 3. Network-attached storage devices and home servers * Social engineering is any technique that uses social skills to generate human interaction that entices individuals to reveal sensitive information * Pretexting involves creating a scenario that sounds legitimate enough that someone will trust you * Phishing lures internet users to reveal personal information such as credit card numbers, Social Security numbers or other sensitive information that could lead to identity theft * Pharming is when malicious code is planted on your computer that alters your browser’s ability to find web addresses * A hoax is an attempt to make someone believe something that is untrue * Hoaxes target a large audience and are generally perpetrated as practical jokes, agents of social change or merely to waste people’s time

Protecting Your Physical Computer Assets * Computers are delicate devices and can be damaged by the adverse impact of keeping them in a poor environment or by abusing them * Sudden movements (such as a fall) can damage your notebook computer or mobile device’s internal components * Electronic components do not like excessive heat or excessive cold * Unfortunately, computers generate a lot of heat, which is why they have fans to cool their internal components * Make sure that your place your computer so that the fan’s input vents are unblocked so that air can flow inside * A fan drawing air into a computer also draws in dust and other particles, which can wreak havoc on your system * Keeping the room where your computer is located as clean as possible * Food crumbs and liquid can also damage keyboards and other computer components * Power surges occur when electrical current is supplied in excess of normal voltage * A surge protector is a device that protects your computer against power surges * Surge protectors contain two components that are used to protect the equipment that is connected to them: Metal-oxide varistors (MOVs) and the ground wire * Surge protectors won’t necessarily guard against all surges; lightning strikes can generate high enough voltages that can easily overwhelm a surge protector * Computers can develop software glitches caused by a loss of power if not shut down properly * Mission-critical computers such as web servers often are protected by an uninterruptible power supply (UPS), which is a device that contains surge protection equipment and a large battery * To prevent your laptop from being stolen, you can attach a motion alarm to it; when you leave your laptop, you use a small device called a key fob activator or punch in a code to activate the alarm * Chaining a laptop to your work surface can also be another effective way to prevent theft * Notebook computers can be protected from theft either by attaching alarms to them or by installing software that will help recover the computer (if stolen) and by reporting the computer’s whereabouts when it’s connected to the internet

Chapter 10 – Behind The Scenes: Building Applications

System Development Life Cycle (SDLC) An organized process (or set of steps) for developing an information processing system.

* 6 steps involved in a common SDLC * System is sometimes referred to as a “waterfall” system (each step is dependent on the one prior) or a “spiral” system (so a group that is supporting the work of another group will work concurrently with that group on development)

1. Problem and Opportunity Identification: * Corporations are always attempting to break into new markets, develop new sources of customers, or launch new products * Whether solving existing problems or exploiting an opportunity, corporations usually generate more ideas for systems than they have the time and money to implement * Large corporations form a development steering committee to evaluate systems development proposals and then review ideas and decide which projects to take on regarding available personnel and funds. 2. Analysis: * Analysts explore in depth the problem to be solved and develop a program specification (clear statement of goals/objectives of the project) * At this phase, the first feasibility is performed which determines whether the project should be pursued * Having a great idea doesn’t mean the company has the technical expertise, financial or operational resources to develop it * When the project is feasible, analysis team studies the current system (if there is one) and considers what the user requirements of the wanted system are, then analysts recommend a solution/plan of action 3. Design: * Goal: to design a system that details the software, inputs and outputs, backups and controls, and processing requirements of the problem * In this phase “make or buy” decision is made * Once system plan designed, a company evaluates the existing software packages to determine whether it needs to develop a new piece of software or can buy something already on the market and adapt it to fit its needs 4. Development and Documentation: * Actual programming takes place * First part of the program development life cycle (PDLC) 5. Testing and Installation: * Testing the program to ensure it works properly then installing it to be used

6. Maintenance and Evaluation: * Once installed, its performance must be monitored to determine whether its meeting the needs of the users or not * If Bugs (errors) are found and were not detected in the testing phase must be corrected

Programming process of translating a task into a series of commands a computer will use to perform that task
Involves:
* Identifying which parts of a task a computer can perform * Describing those tasks specifically * Translating description into the language used by the computer’s central processing unit (CPU)

Program Development Life Cycle (PDLC) A number of stages (5), from conception to final deployment, which a programming project follows

1. Describing the Problem (The Problem Statement)
- Programmers must develop a complete description of the problem 2. Making a Plan (Algorithm Development) * Algorithm: set of specific, sequential steps that describe in natural language exactly what a computer program must do to complete its task 3. Coding (Speaking the Language of the Computer) * Algorithm translated into programming code * When coding the algorithm, programmers must think in terms of the operations that a CPU can perform 4. Debugging (Getting Rid of Errors) * Code goes through process of debugging where the programmers find/repair any errors in code 5. Finishing the Project (Testing and Documentation) * Software tested by programming team and users of program * Results are documented * Users are then trained to use the program efficiently

Describing the Problem: The Problem Statement (#1)

Problem Statement  Clear description of what tasks the computer program must accomplish/how the program will execute these tasks and respond to unusual situations

How do programmers create problem statements?
The goal in creating a useful problem statement is to have programmers interact with users to describe the data, information and method, which are things relevant to creating a useful program. 1. Data (Input) * Raw input users have at the start of the job and feed it into the program * Example: Finding out your daily pay, so entering the hours you works and the pay rate 2. Information (Output) * The result/output users require at end of job * Program produces this information from data * Example: What is your total pay for the day 3. Method (Process) * Process of how the program converts the inputs into the correct outputs * Example: If you work more than 8 hours ($7.50/hr) the pay increases to $11.25/hr. The Program will calculate the hours you entered and whether you worked overtime or not and if you did then it will add 8x7.50 and the number of hours at overtime pay of $11.25/hr.

Problem Statement also Includes:
Error Handling In programming, the instructions that a program runs if the input data is incorrect or another error is encountered
Testing Plan In the problem statement, a plan that lists specific input numbers that the program would typically expect the user to enter. It then lists the precise output values that a perfect program would return for those input values
- Later in a testing process, programmers use the input and output data values form the testing plan to determine whether the program they created works in the way it should

Making a Plan: Algorithm Development (#2)

Algorithm  set of specific, sequential steps that describe in natural language exactly what a computer program must do to complete its task

Do Algorithms appear only in programming?
No, you design and execute algorithms (problem-solving procedures) in your daily life. You might use an algorithm to plan your morning, which would include several steps that summarize all of the decisions you might need to make and show the specific sequence in which these steps would occur.

*Microsoft Visio is one popular flow-charting program made easy for programmers to create and modify flow charts.

Pseudocode is a text-based approach to documenting an algorithm

Binary Decisions A decision point that can be answered in one of only two ways: yes (true) or no (false)

Loop An algorithm that performs a repeating set of actions. A logical yes/no expression is evaluated. As long as the expression evaluates to TRUE (yes), the algorithm will perform the same set of actions and continue to loop around. When the answer to the question is FALSE (no), the algorithm breaks free of the looping structure and moves on to the next step. * 3 important features to look for in a loop 1. A beginning point or initial value 2. A set of actions that will be performed 3. A check to see whether the loop is completed, or a test condition

Control Structures The general term used for keywords in a programming language that allow the programmer to control, or redirect, the flow of the program based on a decision

Different Types of Algorithms:

Top-Down Design is a systematic approach in which a problem is broken into a series of high-level tasks * Top-down design would identify three high-level tasks: Get Input, Process Data and Output Results

Object-Oriented Analysis In object-oriented (OO) analysis, programmers first identify all of the classes (collections of data and methods) that are required to describe completely the problem the program is trying to solve.

Why developers choose object-oriented over top-design?
OO forces programmers to think in general terms about their problem, which tends to lead to more solutions. * Leads to reusability; ability to reuse existing classes of objects from other projects, enabling programmers to produce new code quickly * Inheritance: ability of a new class of objects to pick up all of the data and methods of an existing class automatically and then extend and customize those to fit its own specific needs * Base Class: The original object class from which other classes derive * Derived Class: A class created based on a previously existing class (base class). Derived classes inherit all of the member variables and methods of the base class from which they are derived.

Coding: Speaking the Language of the Computer (#3) * Once the algorithm is created, programmers select the best programming language for the problem and then translate the algorithm into that language. * Translating an algorithm into a programming language is coding. * Programming languages are then translated into patterns of 1s and 0s to be understood by the CPU

How do programmers move from algorithm to code?
When programmers have an algorithm (in the form of a flowchart or a series of Pseudocode statements) they scan the algorithm then identify the key pieces of information it uses to make decisions. After, the programmer can begin converting the algorithm into computer code in a specific programming language.

Programming Language A kind of “code” for the set of instructions the CPU knows how to perform.
- Computer programming languages use special words and strict rules so that programmers can control the CPU without having to know all of its hardware details

Different Categories of Programming Languages: * Can be classified in several major groupings also known as generations * Programming is becoming easier as languages continue to become more closely matched to how humans think about problems

First-Generation Language (1GL)  the actual machine language of a CPU, the sequence of bits (1s and 0s) that the CPU understands

Second-Generation Language (2GL) known as an assembly language which allow programmers to write their programs using a set of short, English-like commands that speak directly to the CPU and give the programmer direct control of hardware resources

Third-Generation Language (3GL) uses symbols and commands to help programmers tell the computer what to do and it makes languages easier for humans to read and remember
- Most programming languages today: BASIC, FORTRAN, COBOL, C/C++, and Java.

Structured Query Language a database programming language that is an example of a fourth-generation language (4GL)

Fifth-Generation Language (5GL) considered the most “natural” of languages as a problem is presented as a series of facts or constraints instead of as a specific algorithm. Example: PROLOG (PROgramming LOGic)

Do you have to use a higher level programming language to solve a problem with a computer?
No. Main advantages of higher -level programming languages are: * Allow programmers to think in terms of the problem they are solving rather than worrying about the internal design and specific instructions available for a given CPU. * They have the capability to produce a program easily that will run on differently configured CPUs * Offer Portability: the capability to move a completed solution easily from one type of computer to another

What happens first when you write a program? * All of the inputs a program receives and all of the outputs the program produces need to be stored in the computer’s RAM while the program is running * Each input and output item that the program manipulates, also known as a variable (a name or symbol that stands for a value), needs to be announced early in the program so that memory space can be set aside * A variable declaration tells the operating system that the program needs to allocate storage space in RAM (ex: int Day; - Java language) * Variable Declaration: A line of programming code that alerts the operating system that the program needs to allocate storage space in random access memory (RAM) for the variable

Additional keywords:

Syntax An agreed-upon set of rules defining how a programming language must be structured.
Statements Sentences in programming code
Keywords A specific word that has a predefined meaning in a particular programming language
Data Types An attribute of a data field that determines what type of data can be stored in the database field or memory location
Operators Any of the coding symbols that represent the fundamental actions of a computer language

* Sections of code that will be used repeatedly, with only slight modification, can be packaged into reusable “containers” or components * Depending on the language, the reusable components are referred to as: functions, methods, procedures, subroutines, modules, or packages.

Compilation is the process by which code is converted into machine language – the language the CPU can understand

Compiler is a program that understands both the syntax of the programming language and the exact structure of the CPU and its machine language, it can also read the “source code” and translate it directly into machine language * Each programming language has its own compiler but sometimes they don’t need one too but will use an interpreter instead * It’s a program you can purchase and install just like any other type of software on your system

Source Code The instructions programmers write in a higher-level language

Executable Program the binary sequence that instructs the CPU to run their code * Can not be read by human eyes because they are pure binary codes * Stored as *.exe or *.com files on Windows Systems
Interpreter it translates the source code into an intermediate form, line by line then each line is executed as it is translated * Compilation process takes longer than the interpretation process because in compilation all of the lines of source code are translated into machine language before any lines are executed * The compiled program will run faster than an interpreted program because the interpreter is constantly translating and executing as it goes

Integrated Development Environment (IDE) is a developmental tool that helps programmers write, compile, and test their programs * Includes tools that support programmers at every step of the coding process * Also includes an editor * Editor: A special tool that helps programmers as they enter the code, highlighting keywords and alerting them to typos * Modern editors automatically indent the code correctly, align sections of code appropriately, and apply color to code comments to remind programmers that these lines will not executed as code * IDE’s also provide help files that document and provide examples of the proper use of keywords and operators * When code editing is finished IDE presents all of the syntax errors in one list so that the programmer can click any item in the list to see a detailed explanation of the error * When item in list is double clicked, the line in the code that contains the error will appear enabling the programmer to repair syntax errors quickly

Code Editing is the step in which a programmer physically types the code into the computer

Syntax Error is a violation of the strict, precise set of rules that define the language * Programmers create syntax errors because when they misspell keywords (ex: BEEGIN instead of BEGIN) or use an operator incorrectly (ex: x= y ++ 2 instead of x= y+2)

Debugging: Getting Rid of Errors (#4)

Debugging The process of repeatedly running a program to find errors and to make sure the program behaves in the way it should

* The testing plan documented in part of the problem statement earlier becomes critically important to programmers in this stage * It clearly lists input and output values, showing how the users expect the program to behave in each input situation * The testing plan must contain enough specific examples to test every part of the program

Logical Error Mistake in the design and planning of the algorithm itself rather than in the use of syntax in the coding

Runtime Error An error in the problem logic that is only caught when the program executes

Debugger A tool that helps programmers step through a program as it runs to locate errors

Finishing the Project: Testing and Documentation (#5)

* After debugging, testing the program takes place (Internal Testing) * The internal testing makes sure the program behaves as described in the original testing plan * Any differences are reported to the programming team * After internal testing there is external testing then beta testing * Before the public release, software is often provided free or at a reduced cost in a beta version to certain test sites or to interested users * Ex: Microsoft Windows and Microsoft Office are available for free beta download for months before the official public release * If there are problems found after beta testing the manufacturer will make changes before releasing the product to other manufacturers (RTM- release to manufacturers) * After the RTM is issued the product is in GA (General availability) and can be purchased by the public

Software Updates A downloadable software module that repairs errors identified in commercial program code (also known as service packs)

Programming Languages: Many Languages for Many Projects

* Wide variety of programming languages have been developed * Programming languages often share common characteristics, each language has specific traits * A quick way to determine which languages are popular is to examine job postings for programmers * Languages most in demand: C/C++ and Java * In banking and insurance industries: COBOL is the common programming language * Pascal is the only modern language that was specifically designed as a teaching language * Many colleges and universities have selected to have students begin with Java or C++ * To select the right language for a specific project a programming team considers several factors: Space available, Speed required, Organization resources available and the type of target application.
Visual Programming A technique for automatically writing code when the programmer says the layout is complete. It helps programmers produce a final application much more quickly

Prototype A small model of a computer program, often built at the beginning of a large project * Is a form of Rapid Application Development (RAD)

Rapid Application Development (RAD) a method of system development in which developers create a prototype first, generating system documents as they use and remodel the product * An alternative to the waterfall approach of systems development

Visual Basic (VB) A programming language used to build a wide range of Windows applications quickly * Strength of VB: it’s simple and has a quick interface * Has grown from its roots in the language BASIC (Beginner’s All-purpose Symbolic Instruction Code) to a sophisticated object-oriented language

Microsoft.Net is a software development environment designed to let Web sites “talk” to each other easily * .NET framework introduces Web services, which provide a standard way for software to interact * Web Service: is a program that a Website uses to make information available to other Web sites

C and C++ originally developed for system programmers * Provides higher-level programmers to manipulate the system memory and CPU registers directly * C is highly attractive to “power” programmers * Most modern operating systems written in C: Windows Vista, Windows 7, Mac OS X, and Linux * C++ takes C to an object-oriented level * Difference from C: extended language with additional keywords, better security, and more support for the reuse of existing code through object-oriented design * For “number crunching” use C/C++

Java A platform-independent programming language that Sun Microsystems introduced in the early 1990s, it quickly became popular because its object-oriented model enables Java programmers to benefit from its set of existing classes * Java is architecture neutral meaning Java code needs to be compiled once then can run on many CPUs * This is because the target computer runs a Java Virtual Machine (VM) (software that can explain to the Java program how to function on any specific system) * Does not perform as fast as C++
*C# - created by Microsoft to compete with Java

Java Applet small Java based program

HTML (HyperText Markup Language)/XHTML (eXtensible HyperText Markup Language) series of tags that modify the display of text * Not programming languages * Adobe Dreamweaver and Microsoft Expression Web present Web page designers with an interface that is similar to a word processing program helping programmers to write in HTML and XHTML

Tags Tags control how a Web browser will display the text, images, and other content tagged in the HTML and XHTML

Scripting Language is a simple programming language that is limited to performing a set of specialized tasks * Scripts allow decisions to be made and calculations to be performed * Popular scripting languages work well with HTML including: JavaScript, VBScript, and PHP (Hypertext Preprocessor)

JavaScript a scripting language that is often used to add interactivity to Web pages

VBScript a subset of Visual Basic, to introduce dynamic decision making into Web pages

Dynamic Decision making  the page can decide how to display itself based on the choices the reader makes

* To build Web sites with interactive capabilities, programmers use Active Server Pages (ASP), Java Server Pages (JSP), or the scripting language PHP (Hypertext Preprocessor) to adapt to the HTML or XHTML

Adobe Flash a software product for developing Web-based multimedia * Has its own programming language named ActionScript (similar to JavaScript)

SilverLight Microsoft’s competing product that supports the development of rich multimedia and interactive Web applications

AJAX (Asynchronous JavaScript And XML) allow the creation of Web applications that can update information on a page without requiring the user to do a page refresh or leave the page

eXtensible Markup Language (XML) enables designers to define their own data-based tags, making it much easier for a Web site to transfer the key information on its page to another site

Objective C has been used to develop applications for Mac OS X for quite a few years but is seeing a huge increase in interest with the explosion of new devices (iPhone, iPad and iTouch)

CIS - Chapter 11 – Database and Information Systems * Databases – are collections of related data that can be easily stored, sorted, organized and queried * Makes data more meaningful and useful * Attempting to turn data into information * Problems with lists: * Inability for data to be shared * Data redundancy * Any time complex info needs to be organized, or more than one person access it, a list is no longer efficient – you need a database * Data Redundancy – amount of duplicated data between two lists * Data Inconsistency – if info is overlooked in one list that needs to be changed, it is not consistent with the rest of the lists * Hard to tell which entry is correct * Data could also be added to a list in an inconsistent format – confusion * Another problem is how to handle incomplete data – is it entered? Or just missing? * Advantages of Using Databases: * Can store and retrieve large quantities of information easily * Enable information sharing * Only one file is kept, increases efficiency, no need for multiple lists * Promote data integrity – means that the data is accurate and reliable * Data centralization – helps ensure data integrity * Allow the flexible use of data * Allows you to reorganize data in a variety of ways * Can manage and process larger amounts of data more efficiently * Disadvantages of Databases: * Complex to construct and administer * Time consuming and expensive to set up * Need a database administrator or database designer * Data privacy is an issue – lots of information in databases * Database Terminology: * Three main components – fields, records and tables * Fields – a category of information in a database is stored in a field * Are displayed in columns, has a field name * Text fields, numeric fields, computed fields, date fields, memo fields, object fields, hyperlink * Field size – defines the max number of characters a field can hold * Ex – size 5, can have number up to 99999 * Record – a group of related fields * Table – a group of related records * Primary Keys –the unique field – making a primary key and ensuring it is unique make it impossible to duplicate records (ex – using a social insurance number, driver’s license #, plate #, order #) * DATABASE TYPES: * Three major types – relational, object-oriented, multi-dimensional * Relational Database – organizes data in table format by logically grouping similar data into relations * Tables are linked to each other by including their primary keys in other tables with related information * Invented by E.F Codd in 1970 * Use structured query language – SQL * Object-Oriented Databases – stores data in objects, not in tables * Contains not only data, but also methods for processing or manipulating that data * Can store more types of data than relational, and access it faster * Can handle unstructured data – nontraditional data such as audio, video, pictures, extremely large documents – is all known as binary large object (BLOB) * Are based on complex models * Use object query language (OQL) * Multidimensional Databases – stores data in multiple dimensions (cube format) as opposed to relational databases, which store data in two-dimensional tables * Measure attribute – the main type of data that the cube is tracking * Feature attributes – describe the measure attribute in some meaningful way * Two main advantages – they can be easily customized and process data much faster * Ex – sites like eBay are set up using multi-dimensional = fast * DATABASE MANAGEMENT SYSTEMS: BASIC OPERATIONS * Database management system (DBMS) – is a specially designed application software (ex – Oracle or Microsoft Access) that interacts with the user, other applications, and the database to capture and analyze data – four main operations: * Creating databases and entering data * Viewing (or browsing) and sorting (indexing) data * Extracting (querying) data * Outputting data * Creating Databases and Entering Data: * Data dictionary- a description of the data – defines the name, data type, length of each field * Called the field properties box in Access * Set default values – the values the database will use for the field unless the user enters another value * Metadata – integral part of the data dictionary – data describing other data * Input Forms – make it easy to transfer from other electronic sources * Provides a view of the data fields to be filled, with appropriate labels to assist users in populating the database * Data Validation – process of ensuring that data is correct and complete * Range Checks – ensure that data entered into the database falls within a certain range of numbers * Field constraints – properties that must be satisfied for an entry to be accepted into the field * Completeness check – ensure that all fields defined as ‘required’ have been entered * Consistency check – compares values of two or more fields to see if they are reasonable * Alphabetic check – confirms that only textual characters are entered in a field * Numeric check confirms that only numbers are entered in the field * Can browse and sort (index) databases * Extracting or Querying data: * Database query – is a question or inquiry you ask the database so that it provides you with the records you wish to view * Query language – that the software uses to retrieve and display records * Outputting Data: * Summary data reports – summarize data with the database and compile a report * Export – export data to other applications * RELATIONAL DATABASE OPERATIONS: * Relationships – links between tables that define how data is related * Need to have a common field * One to one relationship – indicates that for each record in a table there is only one corresponding record in a related table * One-to-many relationships – more common – characterized by a record in one table * Many-to-many relationships – characterized by records in one table being related to multiple records in a second table and vice versa * Normalization of Data: * Goal is to reduce data redundancy by recording data only once * But tables must still work well enough together to enable you to retrieve data when needed * Foreign key – the primary key of another table that is included for purposes of establishing relationships that exist with the other table * Referential integrity – means that for each value in a foreign key of one table, there is a corresponding value in the primary key of the related table * Helps to prevent inconsistent data from being entered in two tables * DATA STORAGE: * Data Warehouse – is a large scale electronic repository of data that contains and organizes all the data related to an org in one place * Consolidate info from different sources to present an enterprise wide view of business operations * Is organized by subject * Is time-variant data – doesn’t pertain to one period in time * Populating Data Warehouses: * Can come from three places: * Internal sources- company databases * External sources – suppliers, venders, etc * Customers or visitors to a company’s website * Click stream data – each click a user makes as they navigate a website * Helps measure the effectiveness of a website * Data Staging: * No two source databases are the same –formats are often different * Data needs to be ‘staged’ before entering the data warehouse * Three steps: * Extraction of the data from the source databases * Transformation (reformatting) of the data * Storage of the data in the warehouse * Online Analytical Processing (OLAP) software – provides standardized tools for viewing and manipulating data in a data warehouse * Key feature – enables flexible views of the data * Data Marts: * Small slices of data warehouses * Pertains to a single department (instead of entire enterprise) * MANAGING DATA: INFORMATION SYSTEMS * Information Systems – are software based solutions used to gather and analyze information * Databases, data warehouses and data marts are all parts of information systems because they store the info that makes info systems functional * Fall into 1 of 5 categories: * Office support systems * Transaction processing systems * Management information systems * Decision support systems * Enterprise resource planning systems (ERP) * Office Support Systems (OSS) - Is designed to assist employees in accomplishing their day to day tasks and improve communications (Example – Microsoft office ) * Transaction Processing Systems (TPS) – used to keep track of everyday business activities * Batch processing – means that transaction data is accumulated until a certain point is reached, and then several transactions are processed at once * Real time processing – means that the database is queried and updated while the transaction is taking place * Online transaction processing (OLTP) – ensures that the data in the TPS is up to date * Management Information Systems (MIS) – provides timely and accurate info that enables managers to make critical business decisions * Is an outgrowth from TPS * Detail reports – from TPS – provides a list of transactions that occurred during a certain time period * Summary reports – MIS – provide a consolidated picture of detailed data * Usually calculations or charts and graphs * Exception reports – MIS – shows conditions that are unusual or that need attention by users of the system * Decision Support Systems (DSS) – is designed to help managers develop solutions for specific problems * Uses data from database and data warehouses, but also enables users to add their own insights and experiences and apply them to the situation * Internal data sources – maintained by the same company that operates the DSS * Customers, ordering patterns, inventory levels, etc * External data sources – include any source not owned by the company – such as customer demographics, mailing lists, gov’t info, etc * Model Management System (MMS) – is software that assists in building mgmt models in DSS’s * Knowledge Based Systems – provides additional intelligence that supplements the user’s own intellect and makes the DSS more effective * Expert system – that tries to replicate the decision making processes of human experts to solve specific problems * Natural language processing (NLP) system – enable users to communicate with computer systems using a natural spoken or written language as opposed to using computer programming languages * Ex- users with disabilities who cannot use a keyboard, speech recognition * Artificial intelligence (AI) – is the branch of computer science that deals with the attempt to create computers that think like humans * Fuzzy logic – enables the interjection of experiential learning into the equation by considering probabilities * Enterprise Resource Planning (ERP) Systems – broad based software systems that integrate multiple data sources and tie together the various processes of an enterprise to enable info to flow smoothly * Use a common database to store and integrate info to enable the info to be used across multiple areas of the enterprise * DATA MINING: * Is the process by which great amounts of data are analyzed and investigated * Objective is to spot patterns or trends within the data that would otherwise not be obvious * Main reason – to understand their customers better * Managers make their data meaningful through the following activities: * Classification – define data classes to help spot trends * Estimation – assign a value, based on a criteria, to data * Affinity grouping (association rules) – which data goes together * Clustering – organizing into subgroups * Description and visualization – having a clear picture of data – visualize it * Ethics and databases – pages 564

Chapter 12 – Behind the Scenes: networking and security in the business worlds

Networking Advantages * A networks is a group of two or more computers (or nodes) that are configured to share information and resources * The advantages of networks for business are: * Networks increase productivity – by sharing data and peripherals with co-workers and communicating with them efficiently * Networks enable expensive resources to be shared * Networks facilitate data sharing – networked databases can serve the needs of many people at one time and increase the availability of data * Networks enable software sharing * Networks facilitate internet connectivity – share internet * Networks can enable enhances communication – email and instant messaging are extremely powerful when employed on a network
Networking disadvantages * Business networks require network administrates that have training in computer and peripheral maintenance and repair, networking design, and the installation of networking software * Operating a network requires special equipment and software
Client/Server Networks * Aside from the smallest networks, such as p2p networks, which are typically used in homes, the majority of computer networks are based on the client/server model * A client/server network (also called a server-based network) contains servers as well as client computers * The main advantage of a client/server relationship is that it makes data flow more efficiently than in p2p networks * Servers can respond to requests from a large number of clients at the same time * P2P networks should not be used beyond 10-users * Client/server networks have increased scalability; With a scalable network, more users can be added easily without affecting the performance of the other network nodes * P2P networks are decentralized – which means that users are responsible for creating their own data backups and providing security for their computers, however, client/server networks are centralized – all clients connect to a network that performs that task for them
Classifications of Client/Server Networks: LANS WANS and MANS * A local area network (LAN) is a generally small group of computers and peripherals linked together over a relatively small geographical area * Wide area networks (WANS) comprise large numbers of users or separate lans that are miles apart * Sometimes government organizations or civic groups establish WANS to link users in a specific geographic area such as within a city or country; a WAN of this type is known as a metropolitan area network (MAN) * A personal area network (PAN) is a network used to connect wireless devices such as Bluetooth-enables devices that are in close proximity to each other. Generally only span 30 feet of the person’s body * An intranet is a private network set up by an entity (such as a business, charity, or government organization) that is used exclusively by a select group of individuals (employees, customers, suppliers, volunteers, supporters, etc.) and is not accessible by unauthorized individuals * An area of an intranet that only certain corporations or individuals can access is called an extranet
Security tools for intranets and extranets * Intranets and extranets often use virtual private networks to keep information secure; A virtually private network uses the public internet communications infrastructure to build a secure, private network among various locations * The main technology for achieving a VPN is called tunneling, where data packets are placed inside other data packets
Constructing Client/Server Networks
Several components: * Server: At least one computer that functions solely as a server * Network topology: The layout of the network * Transmission media: Data needs a way to flow between clients (cable or wireless) * Network operating system: A specialized software that enables the network to function * Network adapter : also known as network interface cards and be attached to each device on the networks * Network navigation device: Routers, switches, and bridges are needed to move data signals around the network
Servers
* Workhorses of the client/server network * A dedicated server is used to fulfill one specific function (such as handling email) * An authentication server is a server that keeps track of who is logging on to the network and which services on the network are available to each users * A file server is a server that stores and manages files for network users * A print server manages client-requested printing jobs and a print queue is a software holding area for print jobs * Application server acts as a repository for application software * A database server provides client computers with access to information stored in a database * A communications server handles all communications between the network and other networks, including managing internet connectivity * A web server is used to host a website so it will be available through the internet; They run specialized software such as Apache and Microsoft Internet Information Services (IIS)
Network Topologies * Bus topology: all computers are connected in sequence on a single capable, not used much anymore, needs an access method which controls which computer is allowed to use the transmission media at a certain time, has a risk for data collision which results in loss of data * Ring topology: configuration resembling a circle, data flows around the circle in one direction only, data passed using a special data packet called a token, a ring topology is an active topology because each node on the network is responsible for retransmitting the token or the data to the next node on the ring * Star topology: A star topology is the most widely developed client/server network layout in homes and business because it offers the most flexibility for the lowest price, the nodes connect to a central communications device called a switch in a pattern resembling a star, the switch receives and retransmits singles to the nodes on the network, it is an active topology, it is an Ethernet network, it uses carrier sense multiple access with collision detection (CSMA/CD) to avoid data collisions
Transmission Media * Can be cable or wireless communications technology, comprise the routes data takes to flow between devices on the network * Most home networks use either twisted-pair cable (phone wire or Ethernet) or electrical wires as transmission media; For business networks, the three main cable types that are used today are twisted pair, coaxial, and fiber optic
Factors in choosing a cable type: * Maximum run length * Bandwidth - The amount of data that can be transmitted across a transmission medium in a certain amount of time * Bend radius (flexibility) * Cable cost * Installation costs * Susceptibility to interference – Two types: Electromagnetic interference (EMI) and radio frequency interference * Signal transmission methods – coaxial and twisted pair cable send electrical impulse down conductive material to transmit data signals, fiber optic transmit data as pulses of light
Twisted-Pair cable * Consists of copper wires twisted around each other and covered by a protective sheath * If the twisted-pair cable contains a layer of foil shielding to reduce interference it is known as shielded twisted-pair (STP), otherwise it is unshielded twisted-pair UTP)
Coaxial Cable * Copper core, solid layer of nonconductive insulating material, a layer of braided metal shielding covers the insulation to reduce interference, and an external jacket of light-weight plastic covers the internal cable components
Fiber-Optic Cable * Composed of a glass or plastic fiber where the data is transmitted, a protective layer of glass or plastic cladding is wrapped around the core to protect it and an outer sheath is added for extra protection, often made of Kevlar
Wireless Media Options * Wireless media are usually add-ons that extend or improve access to a wired network. In the corporate environment, wireless access is often provided to give employees a wider working are * Wireless networks in the US are currently based on the 802.11 standard, also known as WIFI
Network Operating Systems * A network operating system needs to be installed on each client computer and server connected to the network to provide the services necessary for them to communicate * P2p networks don’t need this * Nos software is specifically designed to provide server services, network communications, management of network peripherals, and storage
Network Adapters * Network adapters are devices that perform specific tasks to enable computers to communicate on a network * Network interface cards (NICs) are a type of network adapter installed inside computer * Some network adapters plug into usb port * Network adapters generate high powered network transmissions, are responsible for breaking the data into packets and preparing the packets for transmission across the network, they act as gatekeepers for information flowing to and from the client computer * Ethernet is the standard communications protocol (rules) used on current networks and the adapter cards today are Ethernet compliant * Wireless networks require a wireless network interface card (wireless NIC) and the network must be fitted with wireless access point (WAP) * A special communications software called a device driver is installed on all client computers in the client/server network and they enable the network adapter to communicant with the servers Operating system and the computers OS
Network Navigation Devices * Each network adapter has a physical address called a media access control (MAC) address, and is made up of six two-position characters * A mac address is used for identification purposes internally on a network * A frame is a container that can hold multiple data packets * The NOS software assigns the appropriate MAC address to the frame * MAC address filtering , where only a certain list of addresses are allowed on the network, is a useful security tool on home networks and small business networks
Repeaters and Hubs * A repeater amplifies signals and retransmits it * A hub receives a signal from a device, reconstructs it, and transmits it to all other ports on the hub * Hubs are uncommon in modern networks
Switches and Bridges * A switch is basically a “smart” hub; It uses the MAC address of the data to send the data only to the recipient instead of all devices on the network * When a corporate network grows in size, performance can decline, because many devices compete for transmission time on the network media; To solve this problem a network can be broken into multiple segments known as collision domains and a bridge is used to send data between these collision domains
Routers
* Designed to send information between two networks, uses MAC and IP addresses
Network security for client/server networks * Client/server networks offer more security than p2p networks * ID and passwords can be required on a client/server network * Some sources of security threats are: Human errors and mistakes, Malicious human activity, Natural events and disasters
Authentication
* The process whereby users prove they have authorization to use a computer network * A possessed object is any object that a user carries to id himself and that grants them access to a computer system or facility (ID card, key card etc.) * A brute force attack is delivered by a software that tries many combinations of letters, numbers, words, or pieces of a user ID in an attempt to gain access
Physical Protection Measures * An access card reader is a device that reads information from a magnetic strip on the back of a credit card-like access card (ex. Student ID ) * A biometric authentication device uses some unique characteristic of human biology to id authorized users (ex. Fingerprints or palm prints)
Firewalls
* Involves packet screening- examining incoming data packets to ensure that they originated from or are authorized by valid users on the internal network; The router does this * Most large networks add a bastion host, which is a heavily secured server located on a special perimeter network between the company’s secure internal network and the firewall * A bastion host is often conjured as a proxy server; A proxy server acts as a go-between, connecting computers on the internal network with those on the external network (Internet) All requests to and from the Internet must pass through the proxy server