It is common for people to think that there isn't a difference between an interpreter and a translator. In reality there is a huge difference. They actually require different skills as well. To be able to tell what the difference is you need to understand what it is that each service offers. On the most basic level it seems as though they are quite similar.
One service translates spoken words while the other one translates written words. The main difference is how the job is carried out, the pressures, requirements, skills, and talents. A translator must have the ability to write well and also be able to express words, phrases, innuendos and other linguistic nuances between languages on paper. A translator has the luxury of time, resources, reference materials, as well as the freedom to work on their own schedule. The pressures are limited to a time schedule.
Translators only get work in their native languages to assure accuracy in both linguistic and cultural senses. It could be said that translators are not totally bilingual. These types of translators may be able to effectively deal with written sources but fail when it comes to orally translating which requires a totally different skill.
Interpreters have the ability to translate spoken words in to two directions. They do this without using any resources or reference material, using only their own expertise and knowledge. Interpreters are required to be able to locate linguistic solutions to problems immediately. The pressure in this line of work is much more intense.
Interpreters are also required to be able to act as a bridge between people, relaying tone, intentions, as well as emotions. Interpreters are caught in the middle and must demonstrate extreme professionalism and diplomacy. A simultaneous interpreter has the job of quickly digesting what one person is saying before immediately translating the information to another person in a different language.