Interpreting and translation are two closely related linguistic disciplines. Yet they are rarely performed by the same people. The difference in skills, training, aptitude and even language knowledge are so substantial that few people can do both successfully on a professional level.
On the surface, the difference between interpreting and translation is only the difference in the medium: the interpreter translates orally, while a translator interprets written text. Both interpreting and translation presuppose a certain love of language and deep knowledge of more than one language.