R is a programming language and software environment for statistical analysis and graphics. It originated from S, a statistical programming language developed in the 1970s. R was first released in 1993 and has since grown in popularity due to its ability to run on Linux, Windows and Mac operating systems. It allows users to contribute additional packages to extend its functionality. Getting help in R can be obtained through manuals, online searches, and mailing lists. R has a command line interface but various graphical user interfaces and integrated development environments are also available. Everything in R is an object that has a class and methods, with common functions to define classes, create objects, and extract object elements.