1) Elihu was a character in the Book of Job who appeared after Job's three friends had spoken. 2) There are several theories about who Elihu was, such as another friend of Job, a mediator sent by God, or even the adversary (Satan) in disguise. 3) The identity of Elihu is ultimately unclear and not directly revealed by God, so his precise role remains uncertain, but the overall lessons from Job about reliance on God's grace remain unaffected.