What is the difference between a translator and an interpreter?

What is the difference between a translator and an interpreter?
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 takes oral communications from one language to another, while a translator transposes written text from one language to another. Both interpreting and translation presuppose a certain love of language and deep knowledge of more than one tongue.

To negotiate with foreign investors, to help a doctor with a non-English speaking patient, to convey a conference presentation, you will need an interpreter. To translate books, newspaper articles, contracts, correspondence, you will need the services of a translator. Interpreters concentrate on accuracy and speed. Translators focus on producing a clear, error-free, legible document in the style of the original version