How does traction control work?

When driving in rain, I felt my car slide, whereupon my brakes suddenly pulsed and I stopped sliding. Google tells me that traction control intervened to restore traction, but further googling is more or less silent on the physics of this.

The closest I can find is that the wheel which loses traction spins faster than the rest, and the traction control system slows that particular wheel. But even so I’m not sure why it would help.