Translation is a process performed between different languages that requires a person (the translator) to understand the meaning that a writer or speaker intended to communicate to an original audience in the source language, and then to express that same meaning to a different audience in the target language.
Translators in general have different reasons for doing their work. Their reasons depend on the kind of document they are translating, and on the needs of the person who has asked them to translate it. In the case of Bible translation, people usually do their work because they want the Bible's ideas to affect the target language readers in the same way that the original readers and hearers of the biblical texts were affected. Because God's ideas in the Bible lead us to eternal life with him through Jesus Christ, translators want the target language readers to know his ideas.
There are various ways in which we can represent the ideas in a source text: we can put them into a list, we can summarize them using far less space on the written page, we can simplify them (as we often do in children's Bible story books and in other kinds of Bible helps), or we can even put them into diagrams or charts. However, Bible translators usually try to present the biblical ideas as completely as possible. This also means that they try to produce in translation the same kinds of documents as the original documents (a prophecy for a prophecy, a letter for a letter, a book of history for a book of history, etc.) Also, they try to recreate the same **tensions** in the translation that exist in the source texts.
Examples of tension occur when a reader wonders what will happen next to the participants in a story, or when a reader follows the argument, encouragement, and warnings of an epistle writer or of a conversation that is reported in the text. A reader can feel tension when reading a psalm, since the praises of God affect the psalmist in various ways. When reading an Old Testament prophetic book, the reader can feel tension rise as the prophet condemns people for their sin, or as he warns them to turn back to God. Tension may also be felt when reading about God's promises for the future, as one considers when God fulfilled those promises, or when he will fulfill them.
Another way to talk about recreating the tensions in the source text is to say that the translation should have the same effect on the target audience that the source text had on the original audience. For example, if the source text is a rebuke to the original audience, the target audience should also feel the translation as a rebuke. A translator will need to think about how the target language expresses rebukes and other types communication, so that the translation will have the right kind of effect on the target audience.