An operating system is difficult to define, but has been called "the layer of software that manages a computer's resources for its users and their applications". Operating systems include … अधिक देखें

Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions … अधिक देखें

The components of an operating system all exist in order to make the different parts of a computer work together. All user software … अधिक देखें

If an application is written for use on a specific operating system, and is ported to another OS, the functionality required by that application may be implemented differently by … अधिक देखें

Multicomputer operating systems
With multiprocessors multiple CPUs share memory. A multicomputer or cluster computer has … अधिक देखें

Unix and Unix-like operating systems
Unix was originally written in assembly language. Ken Thompson wrote B, mainly based on अधिक देखें

A hobby operating system may be classified as one whose code has not been directly derived from an existing operating system, and has few users and active … अधिक देखें