What does the Audi A1's automatic start-stop feature do?

I've heard about the automatic start-stop feature in the Audi A1, but I'm not sure exactly what it does and if it's worth having. Can someone explain it to me?

The automatic start-stop feature in the Audi A1 is designed to improve fuel efficiency by automatically turning off the engine when the car is at a complete stop, such as at a red light. This helps reduce unnecessary fuel consumption and emissions, making it better for the environment and your wallet.