Operating system

What is an operating system ?
An operating system is system software that acts interface between computers system and user. Operating system helps to make communicatinos between users and computers. If there is no operating system , there is no interact between users and computers.
The application programing like word processor, spreadsheet, compilers, web browers work on the top of operating system. In other words, OS provides platform to run the application programs. The platform may be GUI or CUI. The OS controls and co-ordinates the uses of the hardware among the various applications programs for the various users.
We can also view a computer system as consisting of hardware, software and data. The OS provides the means for purpose use of the resources in the operation of the computer system. An OS is similar to government. Like government, it performs no useful function by itself, it simply provides an environment within which other programs can do useful work.
Operating system exists because they offer a responsible way to solve the problem of creating a usable computing system. The fundemental goal of computer system is to execute user programs and to make solving user's program easier. Towards this goal, computer hardware is constructed. Since bare hardware alone is not particulary easy to use, applications program are developed. These programs require certain common operating system such as controlling the I/O devices. The common function of controlling and allocating resources are then brought together into one piece of software, the operating system.