Machine Translation
Machine Translation is "the process whereby a computer has the primary responsibility for the translation of a text. A human may assist in the process through such tasks as pre- or post-editing, but it is the computer, rather than the human, that produces an actual draft translation." (Bowker 2002:147)
Translation memory
The idea behind Translation Memory (TM) is to assist the translator by storing source language documents and their translations in a computer system, segmented into manageable units, generally one sentence long. Over time, enormous collections of sentences and their corresponding translations are built up.
In most TM systems these data are stored in a database containing, in addition to the source and target sentences, information like: creation date and author of each translation unit, information on clients, subject fields etc. A few TM systems use collections of source and target language text files (text corpora) as TMs. TM systems allow translators to recycle these translation units by automatically proposing a relevant translation from the TM as a complete solution or exact match or as a partial solution, also called fuzzy match, whenever an identical or a similar source language sentence occurs again in their work.
A TM tool is a software application integrating a set of translation support tools. Apart from a Translation Memory, these could include among others terminology management, word processing, editing, project management and quality control tools.