How does it differ from CAT?

A CAT (computer-assisted translation or computer-aided translation) tool is software used to support a translator facilitating the translation process.

Its aim is to enhance speed, quality and consistency through various features, such as translation memory, term bases, metrics (file analysis), quality assurance and plug-ins (e.g. for machine translation).

As a result, a CAT tool is mostly used by translators and revisers, while TMSs are used also by project managers. Each TMS has a CAT tool as one of its components.

The most popular CAT tools in the market are:

There are also some free tools for users not requiring sophisticated features: