In general there are some Designers and Producers, they lead the way. Then there is the publisher who has the money and thus can lead as well if he wants to.
There there are programmers, artists, leveldesigners and the like. They all get thrown together in big sacks and beaten by the producers.
Then there is also Q&A which tests the game for bugs and playability until they all puke or wanna commit suicide.
That's about it.
