Unix often pronounced as UNIX is an operating system,developed at Bell Labs in the early 1970's as an interactive time-sharing machine. Ken Thompson, Dennis Ritchie, and others team members are the inventors of Unix. In 1976, Unix has become the first operating system based on C language.
It is a freeware product, with so many extensions and new ideas provided in a variety of versions of Unix. Created just a handy for developers, UNIX was designed to be small, flexible system used primarily by the system programmers.
A combination of the C language and shell (user based command)interfaces from different versions of Unix were standardized under IEEE format as the Portable Operating System Interface (POSIX). Such interface is also known as “Single UNIX specification”. After its division in 1982 from Bell Labs, AT & T began to market UNIX and introduced some standard version of UNIX.With many advantages like portability, flexibility and power, UNIX has become a leading operating system for work stations.