compiler

A compiler is a computer program or set of programs that converts text written in a computer language (the source language) into another computer language (the target language). The original sequence is frequently called the source code and the output called object code. Commonly the output has a form appropriate for processing by other programs (e.g., a linker), but it may be a human-readable text file.

The most common reason for wanting to translate source code is to make an executable program. The name "compiler" is primarily used for programs that convert source code from a high level language to a lower level language (e.g., assembly language or machine language). A program that translates from a low level language to a higher level one is a decompiler. A program that translates between high-level languages is generally called a language translator, source to source translator, or language converter. A language rewriter is generally a program that translates the form of expressions without a modify language.