Friday, 3 February 2017

Function of Operating System

NIELIT O Level Solve Paper
IT Tools and Business Application

Q5 B) Explain the functions of Operating Systems.

Solution : 

Operating system provide interface between user and computer. An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware,driver, require an operating system to function.

functions of OS are following


Memory management

Memory management is the functionality of an operating system which handles or manages primary memory and moves processes back and forth between main memory and disk during execution. Memory management keeps track of each and every memory location, regardless of either it is allocated to some process or it is free. It checks how much memory is to be allocated to processes. It decides which process will get memory at what time. It tracks whenever some memory gets freed or unallocated and correspondingly it updates the status.

Process management

Process management is an integral part of any modern-day operating system (OS). The OS must allocate resources to processes, enable processes to share and exchange information, protect the resources of each process from other processes and enable synchronisation among processes.

Source Wikipedia 

Device Management

An Operating System manages device communication via their respective drivers. It does the following activities for device management −
  •          Keeps tracks of all devices. Program responsible for this task is known as the I/O controller.
  •          Decides which process gets the device when and for how much time.
  •          Allocates the device in the efficient way.
  •          De-allocates devices.

File Management

A file system is normally organized into directories for easy navigation and usage. These directories may contain files and other directions.
An Operating System does the following activities for file management −
·         Keeps track of information, location, uses, status etc. The collective facilities are often known as file system.
  •          Decides who gets the resources.
  •          Allocates the resources.
  •          De-allocates the resource

Other Important Activities

Following are some of the important activities that an Operating System performs −
  •          Security − By means of password and similar other techniques, it prevents unauthorized access to programs and data.
  •          Control over system performance − Recording delays between request for a service and response from the system.
  •          Job accounting − Keeping track of time and resources used by various jobs and users.
  •          Error detecting aids − Production of dumps, traces, error messages, and other debugging and error detecting aids.
  •          Coordination between other softwares and users − Coordination and assignment of compilers, interpreters, assemblers and other software to the various users of the computer systems.