How does the Audi A2's intelligent start-stop system work?

I've heard that the Audi A2 has a unique start-stop system, but I'm not sure how it works. Can someone explain it to me?

The Audi A2's start-stop system works by automatically turning off the engine when the car comes to a complete stop, such as at a red light or in heavy traffic. This helps to reduce fuel consumption and emissions. When the driver releases the brake pedal, the engine quickly restarts. Make sure to keep the brake pedal slightly pressed to avoid unintended engine starts.