Why does the Audi A3 come with a Start-Stop System?

I've noticed that my Audi A3 turns off the engine when I come to a complete stop, but why does it do this? Is it beneficial for my vehicle?

The Audi A3 comes with a Start-Stop System to help improve fuel efficiency and reduce emissions. It automatically shuts off the engine when the car is stopped and restarts it when you release the brake pedal.

Not only does the Start-Stop System improve fuel efficiency, but it also helps reduce wear and tear on your engine and starter motor. This can save you money on maintenance costs in the long run.