How do American Colleges compare to British Universitites?

I always see Amercian campus colleges as depicted in the movies. There are seminars and learning, but there seems to be a strong social element of it. This involves crazy parties, frat groups etc. But what is it really like? I know the movies do exaggerate things, but being a brit i don't really have a clue what its like. Over here we have university, where we achieve degree qualifications. Students often live in halls and go out clubbing and drinking. It would be interesting to find out what the American version is like?