Machine translation, sometimes referred to by the abbreviation MT (not to be confused with computer-aided translation

Computer-assisted translation

Computer-assisted translation, computer-aided translation, or CAT is a form of translation wherein a human translator translates texts using computer software designed to support and facilitate the translation process....

, machine-aided human translation MAHT and interactive translation

Interactive machine translation

Interactive Machine Translation , is a specific sub-field ofcomputer-aided translation. Under this translation paradigm, thecomputer software that assists the human translator attempts to predict the...

) is a sub-field of computational linguistics

Computational linguistics

Computational linguistics is an interdisciplinary field dealing with the statistical or rule-based modeling of natural language from a computational perspective....

 that investigates the use of computer software

Computer software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

 to translate

Translation

Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...

 text or speech from one natural language

Natural language

In the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...

 to another.

On a basic level, MT performs simple substitution

Substitution

Substitution may refer to:- Sciences :* Substitution , a syntactic transformation on strings of symbols of a formal language* Substitution of variables* Substitution cipher, a method of encryption...

 of words in one natural language for words in another, but that alone usually cannot produce a good translation of a text, because recognition of whole phrases and their closest counterparts in the target language is needed.