Unix is an operating system that was developed by Kenneth Thompson and colleagues at AT&T Bell Laboratories in the late 1960's. The program was originally intended for scientists and engineers, although its use has expanded since the inception of Unix. There are now several modifications to the AT&T standard, mostly because Bell Labs distributed the operating system in its source language form. This allowed anyone to modify the system for his or her own purposes. Now, Unix is the operating system on which many network protocols, such as TELNET and FTP, are based.

There are two main types of Unix. System V is produced by AT&T and BSD4.1- 4.3 are produced by The University of California at Berkeley.

Operating systems, including Unix, determine how a computer is to operate, and provide the link between the user and the computer resources. An operating system schedules tasks...