What is the purpose of the Audi A1's start-stop system?

I have noticed that my Audi A1 has a start-stop system, but I am unsure of its purpose. Can you provide some information on why this feature is useful and how it works?

The start-stop system in the Audi A1 is designed to save fuel by automatically turning off the engine when the car is stopped, such as at a red light or in stop-and-go traffic. This feature is especially helpful in city driving, where there is a lot of stopping and starting. Once the brake is released, the engine starts up again immediately.

In addition to saving fuel, the start-stop system also reduces emissions and helps to keep the engine in good condition. It works by using sensors to detect when the car is stationary and then shutting off the engine. The system is able to start up the engine quickly and smoothly when needed.