What is the difference between Interpretation and Translation?

I'm surprised to hear that many people don't know the difference between Translation and Interpretation. Most of the mails I get by clients ask me if I can translate for them. In most cases, they want me to work as Interpreter. Not many people know the difference between Interpretation and Translation.

 In simple words, Interpretation is the translation of spoken words. It is a job where you need great communication skills, speed and like to meet people in person. A Translator can spend weeks without actually meeting clients in person. It's a great job if you like to work from home. As a professional translator you try to find the best possible translation for a written text. Therefore, a translator needs great research and writing skills in the first place. Both professions are similar in a way that you need language skills. Therefore, some translators sometimes work as Interpreter as well. A client who knows your language abilities will ask you not only for interpretation, but also for the translation of documents. For me that is the best way to find translation work, because a direct client will pay better rates than someone you just meet online. Here people look for the fastest and cheapest translator to get the job done.