OS, Components, Functions/Tasks

Operating System

An operating system is a software system. It acts as an interface between a user of a computer and the computer hardware. The operating system provides an environment in which a user may execute programs. The goals of an operating system are to :
Make the computer system convenient for users.
Make the efficient use of the computer hardware.


An operating system is an important part of a computer system. A computer can be viewed to have four components :

Hardware (CPU, memory, I/O devices etc.)
Operating system
Application programs (compilers, database systems, video games, business programs etc.)
Users (people, machines or other computers).


The Tasks of an Operating System

The most important task of an operating system is to process commands and to provide coordination between different processing tasks.

Processing Commands: The operating system interprets instructions entered through the keyboard. When one uses an application program, the program's commands are interpreted by the operating system.

Multitasking: Modern operating system allow to multitask, that is, to perform multiple tasks, at the same time with different programs.

Multithreading: Most application process data and commands sequentially, i.e., when one task is finished they begin another. The application therefore follows a single thread from the begining of a session to the end and individual operations are strung like beads on a necklace.

Multi-user Support: Some operating systems are designed so that many users can be connected to the system at the same time. Multi-user operating systems are also multitasking because the multiple users run their programs at the same time.

Multiprocessor Support: Some application need huge processing power. Some operating systems support multiple processors-in some cases hundreds or even more.

Miscellaneous Tasks: In addition to the processing tasks discussed, an operating system also performs the following tasks:
The operating system continually monitors the system and if it detects something wrong, it outputs an error message.
The operating system manages the use of memory and stop each programs in its own protected space so that a problem with one program will not affect others.
The operating system allocates peripheral devices for different tasks.
To conserve power, power management cuts power at those times when it is not needed.
Management file stored on disks.