A programming language is a system of notation for writing computer programs.
A programming language is usually described in terms of its syntax (form) and semantics (meaning). These are usually defined by a formal language.
A language usually has at least one implementation in the form of a compiler or interpreter, allowing programs written in the language to be executed.
Programming language theory is the subfield of computer science that studies the design, implementation, analysis, characterization, and classification of programming languages.