Why does the Audi A7 use a 48V hybrid system?

I recently saw that the Audi A7 is equipped with a 48V mild hybrid system. How does this system work and why did Audi choose to implement it in the A7?

The 48V mild hybrid system in the Audi A7 uses a small electric motor to assist the engine during acceleration, resulting in improved fuel efficiency and performance. Audi chose to use this system because it allows for a smooth and seamless transition between gas and electric power, providing a more refined driving experience.