A translation unit is a segment consisting of a source text and a target text (where the target text is not required). In the RC-WinTrans localization environment, a translation unit is (in terms of properties and data) the <trans-unit> data element specification of the XLIFF standard.
The primary data of a translation unit includes:
NOTE: The term "translation unit" may also be found in association with other applications or data sources and in these cases usually refers to other data or object types. For example, when used in conjunction with a Trados translation memory, a translation unit is defined as "a segment or sentence pair in source and target languages," and with TMX as "an entry consisting of aligned segments of text in two or more languages."
See also: "Groups."