Absolute motion measures speed and direction relative to the ground. In vehicle dynamics, this is measured using GPS and chassis-mounted accelerometers. It is different from relative motion, which compares one moving part to another, like a wheel spinning relative to the car body.
Modern stability control systems compare these two measurements. If the wheels are spinning but the car's absolute motion shows it is sliding sideways, the system activates. It brakes individual wheels to pull the vehicle back on line.