Why does the Audi A7 have a 48-volt electric system?

I've heard that the new Audi A7 has a 48-volt electric system. What does this mean and what are the benefits of having it?

The 48-volt electric system in the Audi A7 is used to power a number of advanced technological features, such as the electric supercharger and active suspension.

Having a 48-volt electric system allows for smoother and faster start-stop operation, as well as improved fuel efficiency by enabling coasting at speeds between 55 and 160 km/h.

It also enables the use of a mild-hybrid system, which can recover energy during braking and use it to power the vehicle's electrical systems, reducing strain on the engine.