A translator works with different languages. They may read something written in one language and speak it or write it in another language or vice versa. For example, they might read a book in French and then translate it into English. See translation for more information.
In order to convert meanings from one language into another one, translators must be able to know the target language deeply. They are conveying the original meaning of the source text or material to a second language. As a result, translators do not only convert words, which makes it more like an art than a science.
Translators also work to convert speech as well as writing. The United Nations debates are translated as they are spoken, one individual translator for every individual language if it is the General Assembly.
One advantage of professional translation is that it reduces the problems of understanding what is said. On the other hand, there is often a loss of nuance (subtlety) in a translations, especially one done immediately the text is spoken. For this reason, many translators do a rough version immediately, and then work it over later on.