I don't mind explaining positions...
Member: Just your average, every-day member.
Moderator: Moderates one or more forums, does not moderate every forum. Power to post in the staff forum. Close topics, Open topics, delete topics, delete posts, pin threads and un-pin threads.
Super Moderator: Same as above, rather than one or two forums however, they moderate all forums.
Admin: They process submissions, well I assume you know what an admin can do so Yeah. If you're unaware of an admin's powers, feel free to say, and I or another member will inform you.