Translation and interpretation, two different works
Though many use the terms translator and interpreter interchangeably to refer to the person who transmits a message from one language to the other, the truth is that in practice the tasks carried out by them are different.
The translator translates the written language whereas the interpreter translates the oral language. Therefore, while the translator is responsible for translating documents, books, contracts, etc. the interpreter is in charge of simultaneous or consecutive conference interpreting, round table interpretation, whispering, telephone interpretation, etc.
Thus, not only do the translator but also the interpreter have to master both languages but also need to train in the specific discipline or field of knowledge: legal, technical, medical, economics, IT, literature.