An operating system acts as an intermediary between the user of a computer and the computer hardware.
An operating System (OS) is software that manages the computer hardware.
Components of a Computer System
Hardware It provides the basic computing resources for the system. It consists of CPU, memory
and the input/output (I/O) devices.
Application Programs Define the ways in which these resources are use to solve user's computing problems.
e.g., word processors, spreadsheets, compilers and web browsers.
Functions of Operating System
Operating system provides many functions for ensuring the efficient
operation of the system itself. Some functions are listed below.
Allocation of resources to the various processes is
manged by operating system.
Accounting Operating system may also be used to keep track of the
various computer resources and how much and which users are using these resources.
Protection Protection ensures that all access to the system resources is
controlled. When several processes execute concurrently, it should not be
possible for one process to interface with the other or with the operating system itself.
Operating System Services
Many services are provided by OS to the user's programs.
Some of the OS services are listed below
Program Execution The operating system helps to load a program into
memory and run it.
I/O Operations Each running programs may request for I/O opration and for efficiency and protection the users cannot
control I/O devices directly.
Thus, the operating system must provide some means to do I/O operations.
File System Manipulation Files are the most important part which is
needed by programs to read and write the files and files may also be
created and deleted by names or by the programs. The operating system
is responsible for the file management.
Communications Many times, one process needs to exchange
information with another process, this exchange of information can takes
place between the processes executing on the same computer or the
exchange of information may occur between the process executing on the
different computer systems, tied together by a computer network. All these
thing are taken care by operating system.