How does the Audi A6's mild-hybrid technology work?

I've heard that the Audi A6 has mild-hybrid technology, but I'm not sure exactly how it works. Can someone explain it in simple terms?

The mild-hybrid technology in the Audi A6 uses a 48-volt lithium-ion battery and a belt alternator starter to help improve fuel efficiency and reduce emissions. When braking or coasting, the car's kinetic energy is stored in the battery and can then be used to assist the engine during acceleration.

The mild-hybrid system also allows the car to coast with the engine switched off while driving at speeds between 55 and 160 km/h, further improving fuel efficiency. It's a seamless and efficient way to reduce your carbon footprint while driving.

The 48-volt battery also enables the start-stop function, which shuts off the engine when the car is stationary to save fuel. This is especially useful in stop-and-go traffic, and the system can restart the engine in a fraction of a second when you release the brake pedal.