Quick Info On Circuit Training

Hi guys,
someone could give me a quick briefing about circuit training?

I got used to do things like this:
3x10/8/8/8 bench press
3x8 cross over
3xmax dip

and so on, every muscle his own session and there was as 3 or four different muscles trained per work out (for example i perfomanced chest/biceps/abdominals).

I red here some Chad’s and CT’s articles, their way training is completely different, they do like sets with more than one exercise, this look great. So I’m looking for any information, articles, sites, books, I’ll very appreciate your opinion too.