All scooters are two wheel drive. Just like a car, they have a built-in differential to allow the scooter to turn corners. The drive wheels are always on the rear of the scooter. (Rear wheel drive)
The drive wheels are driven by the transaxle which is, in turn driven by a motor or in some cases, two motors. Also, there's a magnetic brake attached to the transaxle. When the rider lets up on the throttle, the magnetic brake is activated to bring the scooter smoothly to a stop.