C is a general-purpose and very powerful programming language. Although it has been often referred to as a “system programming language” because of its usefulness in writing compilers and Operating Systems, it has been used in a variety of other domains.

A number of ideas in C stem from the language BCPL, developed by Martin Richards. The influence of BCPL on C proceeded indirectly though the language B, written by Ken Thompson in 1970 for the first UNIX system on the DEC PDP-7.

C was originally designed for and implemented on the UNIX operating system on the DEC PDP-11, by Dennis Ritchie.

BCPL and B are “typeless” languages, where as C provides a variety of data types. The fundamental types are characters, integers and floating-point number of several sizes. Also, there is a hierarchy of derived data types created with pointers, arrays, structures and unions.