Why does the Audi A3 have a 48-volt mild hybrid system?

I've noticed that some Audi A3 models have a 48-volt mild hybrid system. What exactly is this system for and how does it work?

The 48-volt mild hybrid system in the Audi A3 is designed to improve fuel efficiency and reduce emissions. It uses a small electric motor to assist the gasoline engine, providing extra power when needed and allowing the engine to shut off when coasting or at a stop light.

The mild hybrid system in the Audi A3 also allows the car to enter a coasting mode when driving at higher speeds, where the engine completely shuts off and the vehicle is solely powered by its momentum. This can greatly improve fuel efficiency while still maintaining a smooth driving experience.

The 48-volt mild hybrid system in the Audi A3 also has a regenerative braking feature, which captures energy during braking and stores it in the battery. This energy can then be used to power the car's electrical systems, reducing strain on the engine and improving overall efficiency.