Modern Operating System
2050243-MAJOR IX MODERN OPERATING SYSTEM 1. The operating system is the most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing inputfrom the keyboard, sending output to the display screen, keeping track of filesand directories on the disk, and controlling peripheral devices such as disk drives and printers. 2. The kernel is a program that constitutes the central core of a computer operating system. It has complete control over everything that occurs in the system.
A kernel can be contrasted with a shell (such as bash, csh or ksh in Unix-like operating systems), which is the outermost part of an operating system and a program that interacts with user commands. The kernel itself does not interact directly with the user, but rather interacts with the shell and other programs as well as with the hardware devices on the system, including the processor (also called the central processing unit or CPU), memory and disk drives.
The kernel is the first part of the operating system to load into memory during booting and it remains there for the entire duration of the computer session because its services are required continuously. Thus it is important for it to be as small as possible while still providing all the essential services needed by the other parts of the operating system and by the various application programs. 3. Virtual memory is a feature of an operating system that enables a process to use a memory (RAM) address space that is independent of other processes running in the same system, and use a space that is larger than the actual amount of RAM present, temporarily relegating some contents from RAM to a disk, with little or no overhead. 4. Paging is a method of writing data to, and reading it from, secondary storage for use inprimary storage, also known as main memory. Paging plays a role in memory management
A kernel can be contrasted with a shell (such as bash, csh or ksh in Unix-like operating systems), which is the outermost part of an operating system and a program that interacts with user commands. The kernel itself does not interact directly with the user, but rather interacts with the shell and other programs as well as with the hardware devices on the system, including the processor (also called the central processing unit or CPU), memory and disk drives.
The kernel is the first part of the operating system to load into memory during booting and it remains there for the entire duration of the computer session because its services are required continuously. Thus it is important for it to be as small as possible while still providing all the essential services needed by the other parts of the operating system and by the various application programs. 3. Virtual memory is a feature of an operating system that enables a process to use a memory (RAM) address space that is independent of other processes running in the same system, and use a space that is larger than the actual amount of RAM present, temporarily relegating some contents from RAM to a disk, with little or no overhead. 4. Paging is a method of writing data to, and reading it from, secondary storage for use inprimary storage, also known as main memory. Paging plays a role in memory management