Translators work with documents, interpreters work with the spoken word.
Translators usually work remotely using specialised software such as word processors and web design tools whereas interpreters work on-site along side you and your clients.
Translating and interpreting are two very different skills and, although some people offer both services, it is important not to confuse the two when commissioning work.
Translators and interpreters are usually much better at translating into their mother tongue than they are at translating from their mother tongue into a foreign language. Beware of anyone who tries to convince you otherwise.