How does the Audi A6's hybrid system work?

I heard that the 2021 Audi A6 has a hybrid system. I am interested in learning more about how it works and if it is beneficial for fuel efficiency.

The Audi A6's hybrid system uses a combination of a 2.0-liter TFSI four-cylinder engine and a 12-volt mild hybrid system. The electric motor kicks in during stop-and-go traffic, providing a smoother and more efficient driving experience.

The hybrid system in the Audi A6 allows the car to power off the engine while cruising at speeds between 34 and 99 mph, saving fuel. It also has a coasting function that decouples the engine from the transmission when coasting, reducing fuel consumption.