2004 GRAND PRIX GT QUESTIONS:?

I own a Grand Prix GT 04, and bought it a year used, and have had it for awhile, however when we bought it it came without a owner's manual. I was wondering if anyone knew what the Traction Control on did. It's the on behind my gear shift, however I'm not sure how you use the on considering the traction control turns on automatically... anybody know what this mysterious on actually does?