I have a question, what really is the occult that the Bible condemns?

Obviously people who try to practice magical acts like levitation are part of the occult, but is it supporting the occult to see a movie with magic in it (i.e. Harry Potter) or play a game with magic in it (i.e. Chronicles of Narnia). What about seeing magic shows with people such as David Copperfield?
What about something less blatant like Star Wars that is based off of an 'energy' field, but isn't really magic? Is that occult too? Count me as confused.
Just a little afraid that I do not understand this occult concept..