While the antilock brake system (ABS) helps keep traction while braking, and traction control (TC) helps keep traction while accelerating, it's yaw control that helps you keep traction while turning (or trying not to!) All three systems watch the output of the wheel sensors and take actions based on them; ABS tries to make sure that all wheels are turning at about the same rate, and TC tries to make sure that your use of the throttle doesn't cause them to spin, but yaw control's job is to make sure that the car goes where you are trying to make it go, and that makes it the most complicated out of the three.
Traction control is a name for a computer-controlled system intended to stop wheels from spinning during acceleration. The term is also used (somewhat incorrectly) to describe yaw control, a system designed to stop a vehicle from turning when you don't want it to. Both systems work by watching information from wheel position sensors, typically the same ones used for the antilock brake system (ABS) and then doing either one or both of two things: reducing the engine power output or applying the brakes through ABS.
The Antilock Braking System, or ABS, is a system which seeks to prevent you from locking up wheels on your vehicle through braking. It does this through the use of a hydraulic pump which is installed in line between your brake master cylinder and the brake slave cylinders. This pump reduces braking force when a sensor detects that a wheel has stopped moving, causing the wheel to unlock. The primary benefit of the ABS system is that you can slam on the brakes without skidding, which permits you to steer the vehicle no matter how hard you are attempting to brake.