What is the purpose of trac in a 2001 Olds Intrigue?

Are you talking about the traction on/off button behind the gear shift? I got a 98 intrigue, but haven't exactly figured out why anyone would want to turn it off. It prevents over revving the engine when the wheels begin to spin on snow or ice. It sort of acts like a cut out on the engine so less power can go to the front wheels. Turn it off and it will spin away. Thios is on a 2001 but I'm sure they serve the same function