As a translator, you'll convert written material from one or more 'source languages' into the 'target language', making sure that the translated version conveys the meaning of the original as clearly as possible. The target language is normally your mother tongue.
Transcreation may also be part of the job, which is a mix of translation, localisation (taking into account factors such as cultural nuances) and copywriting, where the text is culturally and linguistically adapted to suit the reader.