Computer Assisted Translation or CAT-software is a type of computer software that human translators use to support and facilitate the translation process. CAT stands for Computer Assisted Translation.
Computer-assisted translations are sometimes called machine-assisted or machine-aided translations (not to be confused with machine translations).
CAT tools divide documents into translation units (TU) also called segments, and present these segments one by one in order to ease and speed-up the translation process. The tools then save the translated segments in a database – the Translation Memory or TM
With each new translation request the translator automatically adapts the TM to facilitate any further translation project. For a new project the CAT tools search the TM for any segment or part of TU that could be reused. Translation units can also be reused for any other purpose, and helps to improve quality, because the translation services are coherent and consistent.