The latest film in the Alien franchise, (as of this writeup) and the earliest film in the timeline, Prometheus sought to answer questions we've had since the beginning, about the origins of the Xenomorph. Further, the movie itself explores the (blog post) questions of the origins of life itself. And more questions, and (blog post) more questions. Lots and lots of questions, really. Answers? Good question.
Source: Prometheus Movie Review - Decker Shado