The predecessor to R, S is a high-level language for data manipulation and analysis. Highly extensible, S is a functional system that treats functions written by users as first-class objects similar to those of the system. Its code is readable and the language is fairly easy to understand, which is why it’s used for statistical and graphical analysis in large applications. 

A programming language is a formal language comprising a set of strings that produce various kinds of machine code output. Programming languages are one kind of computer language, and are used in computer programming to implement algorithms.