OPERATING SYSTEM

All computers require some form of hardware platform to run software; These platforms are called operating systems (OS). An operating system is a program that acts as an interface between the computer user and the computer hardware. The purpose of an operating system is to provide an environment where the user can run programs in a convenient and efficient manner. Operating system is an important part of every computer system. It manages all the resources of the computer system. The operating system is installed in secondary memory, part of which is permanently stored in read-only memory (RAM). Some part of the operating system resides in Random Access Memory (ROM) and the computer starts running this part of the system.

Most modern home computers use some form of Microsoft operating system. Although most computers use Windows, the original Microsoft operating system was called DOS (Disk Operating System). Windows comes in various versions, starting with version 3.x, then 95, 98, XP and now Windows 7. Some computers use IBM's O/S2.

Although most modern Mac versions use version 8.x or 9.x, Apple's Macs use their own operating system starting with OS 1. Apple's latest version is OS 10.1.x. Some computer professionals, Internet Service Providers (ISPs), and mainframe computer users use operating systems such as UNIX, Windows NT or 2000, or server-based operating systems. The operating system controls input and output or directs the flow of information to and from the CPU. Most of this is done automatically by the computer. In short, operating system is one of the most important components of computer software required to run a computer. When the computer is turned on, it must first load the operating system, sometimes called booting up. It checks all its components and usually displays a message if there is a problem. This is also known as Power On Self Test (POST). Booting the system is usually automatic. Once the system is loaded, the user can launch the application or program that he is going to use.

A computer is an electronic device that performs mathematical and non-mathematical operations to obtain results. Its first generation used vacuum tubes. The second generation used much smaller transistors than vacuum tubes. Integrated circuits were used in the third generation. VLSI comes in fourth generation computers and is now moving towards fifth generation parallel computing. An operating system is an essential component of a modern computer. The two main purposes of an operating system are to control the computer's hardware and to provide an interactive interface between the user and the machine. Computers have entered every field of human life and have found their application in various fields like medicine and health care, business, science, technology, engineering, entertainment etc.