Operating System

An operating system is a special kind of system software that is responsible for the management of all activities of the computer and the sharing of computer resources. It is considered the backbone of a computer, managing both software and hardware resources. Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays. They also manage files on computer hard drives and control peripherals, like printers and scanners.

An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs. Users and application programs access the services offered by the operating systems, by means of system calls and application programming interfaces. To run a certain software in a PC, it needs to be compatible with the installed OS.

An Operating System provides services to both the users and to the programs.

• It provides programs with an environment to execute.

• It provides users with services to execute the programs in a convenient manner.

Some of the most important functions of an operating system are:

· Resource Allocation

· Memory Management

· Processor Management

· Device Management

· File Management

· Program execution

· Security

· Control over system performance

· Error detecting aids

· Coordination between other software and users.

Users interact with a computer operating system through Command Line Interfaces (CLIs) or Graphical User Interfaces known as GUIs (pronounced “gooey”). Graphical user interfaces have graphic representation of every process or application. It allows users to navigate with the help of a pointing device (a mouse or a stylus) by clicking on icons, buttons, and menus.

Each operating system's GUI has a different look and feel, so it can cause some difficulties at first when a user switches to a different operating system. However, modern operating systems are designed to be user-friendly, and most of the basic principles are the same.