Ans: An operating system is an essential software component of a computer system. The basic objectives of an operating system are to make the computer system convenient to use and to utilize computer hardware in an efficient manner. We can define an operating system as a large collection of software, which manages the resources of the computer system, such as memory, processor, file system and input/output devices. It keeps track of the status of each resource and decides which will have control over computer resources, for how long and when. In doing so, it provides two basic types of services:
1. It accepts requests from users and from the user’s programs and executes their commands.
2. It optimally manages the hardware resources of the computer which may include CPU, main memory, hard disks, I/O devices, network interface card, etc. The Operating System of a computer is a large program which manages the overall operation of the computer system. On a simple one-user computer the Operating System will:
1. Provide an interface to allow the user to communicate with the computer. This interface may be a text-oriented interface where the user types commands in response to a prompt from the computer or may be a mouse-driven Windows operating system.
2. Control the various peripherals e.g. Keyboard, Video Display Unit (VDU), Printer etc. using special programs called Device Drivers.
3. Manage the user's files, keeping track of their positions on disk, updating them after user makes changes to them etc. An important facility that the Operating System must supply in this respect is an Editor which allows users to edit their files.
4. Provide system facilities, e.g. Compilers to translate from high-level programming languages used by the user to the internal machine