It's actually about clothing design. They start off with about 20 designers who do all different things. Some people design for big names, some people own boutiques, some people are out of school. Each week they have a different challenge, (design for a pregnant lady, design for Diane Von Furstenberg's label, make clothing from items from a supermarket...) and each week one person gets sent home. The top three designers get to show their clothes, and one person wins. They get money to make their own line and a company (I think Bluefly has done it before) sells their clothes.
They have to show their clothes on models each week, and one of the models wins a spread in a magazine.
I really really like the show, I think it's fun.