What is the purpose of the start-stop system in the Audi A4?

I've noticed that my Audi A4 has a start-stop system, but I'm not sure what it does. Can you explain why this feature is included in the car?

The start-stop system helps reduce fuel consumption and emissions by automatically turning off the engine when the car is at a complete stop for more than a few seconds. This feature is especially useful in city driving where there are frequent stops and starts.

In addition to the environmental benefits, the start-stop system also helps reduce wear and tear on the engine, leading to longer engine life and potentially saving you money on maintenance costs in the long run.