An electronic suspension system on your car is an air bag system that is controlled by a computer to give you optimal ride quality on all types of roads. If you have a performance vehicle, this means that the computer will be optimized to give you the most traction and the least amount of body roll during cornering. With a luxury car, the computer will also adapt to maintain a minimum of body roll, but the ride will be much softer than in a performance car. There is an air compressor and a set of valves that are controlled by the computer, which uses inputs from a number of sensors to maintain a stable ride with minimal body roll.
For more info, see What a Swaybar does