From my experience in the world of translation, Translation Memories (TMs) and Term bases (TBs) are sent in mainly by clients who request to translate large projects or small projects but with frequent updates.
In a TB the client may prioritize the translation of certain terms over others, or even mark a translation as a “forbidden term”. In Translation Memories, entire segments can be saved in a special kind of database and later on reflected in another, similar project. This not only benefits the client with regard to delivery times, but it also allows the translator to invest more time in style and fluency and not so much in retranslating something already done in the past. Moreover, and with the help of the “concordance” feature, a TM will help them in researching certain words preferred by the client but not included in the TB.
Some companies will frequently send in various instruction manuals with updates which, more often than not, include content that comes up repeatedly throughout their projects. In this situation, a TM enables the translator to be consistent all throughout. That is, upon translating page 204, when a specific segment of words or paragraph that was translated on page 2 pops up, he/she will be prompted with a linguistic suggestion that will coincide with the one previously used and consequently will add coherence and consistency to the text.
Furthermore, when weeks or even months down the line, an update of the manual is required, the translator won’t have to reach back into the archives and scroll through hundreds of pages in order to gain some context, but rather, can benefit from a Term base that points out that the target term is “device” and not “instrument”.
Aside from enabling the translators to work in a consistent manner, these resources also allow time to be spent in re-reading certain parts or focusing on the fluency of the text rather than on the acquisition of terminology. Frequently clients will send in texts that feature words which appear on the company’s website. It is essential in these cases for the vocabulary which is used on the texts to match that which can be found on the website. TM and TB are a great hand in these cases because it prevents the translator from using other alternatives which do not coincide with those previously used by the company.