Transliteration is the practice of transcribing a word or text written in one writing system into another writing system. It is also the system of rules for that practice.

Technically, from a linguistic point of view, it is a mapping from one system of writing into another. Transliteration attempts to be exact, so that an informed reader should be able to reconstruct the original spelling of unknown transliterated words.

It is not to be confused with translation, which involves a change in language while preserving meaning. Here we have a mapping from one alphabet into another.