Translations are edited by a trained specialist who has experience as a translator and is a native speaker of the target language. The editor checks whether the translation conforms to the agreed purpose, compares the source with the target text, and makes whatever changes or corrections are necessary.
A specialist in the given field checks whether terms are used correctly in a translated text.
A proof-reader reviews the translation to make sure it is orthographically correct as well as readable.
It is often a good idea to review print-ready text one last time to turn up any layout miscues and any stray typographical errors that may remain.