Encoding is the process of transforming information from one format into another. The opposite operation is called decoding.

There are a number of more specific meanings that apply in certain contexts:

• Character encoding is a code that pairs a set of natural language characters (such as an alphabet or syllabary) with a set of something else, such as numbers or electrical pulses.
• Text encoding uses a markup language to tag the structure and other features of a text to facilitate processing by computers. (See also Text Encoding Initiative.)
• Semantics encoding of formal language A in formal language B is a method of representing all terms (e.g. programs or descriptions) of language A using language B.
• Encoding transforms a signal into a form optimized for transmission or storage, generally done with a codec.

The term encoding is often used to refer to encryption, but the term "encoding" implies no use of a key.

Encodings

Encodage