In general, it can be said that there are two extreme approaches in the way one can translate from one language to another. The first is seeking a literal translation, sometimes known as formal equivalence, in which an attempt is made to translate using the words that correspond as exactly as possible in the two languages, allowing, of course, for the grammatical differences but without paying a great deal of attention to context. A second extreme is paraphrasing, sometimes called making a free or loose translation.

One problem with the first approach is that literal translations can be awkward. For example, it might be more “exact” to translate the Spanish obtener as “to obtain,” but most of the time “to get” will do just as well and sounds less stuffy. An obvious problem with paraphrasing is that the translator may not accurately convey the intent of the speaker, especially where precision of language is required. So many of the best translations take a middle ground, sometimes known as dynamic equivalence — trying to convey the thoughts and intent behind the original as close as possible, veering from the literal where needed to do so. Read more.

See: About.com