Introduction

An operating system (OS) is a software program. There are two software categories: application software and system software. The operating system is an example of system software. Operating systems manage computer system hardware and software. The operating system also acts as the primary controlling mechanism for the computer's hardware. Operating System primarily provides services for running applications on a computer system. Some examples of operating systems are UNIX, Mach, MS-DOS, MS-Windows, Windows/NT, Chicago, OS/2, MacOS, VMS, MVS, and VM.