How does the Audi A6's Quattro 4WD system work?

I've heard that the Audi A6 has a Quattro 4WD system, but I don't quite understand how it works. Can someone explain it to me in simple terms?

The Audi A6's Quattro 4WD system uses a center differential that constantly monitors traction and distributes power to each wheel as needed. For everyday driving, it will generally send more power to the front wheels for better fuel efficiency, but can shift power to the rear wheels in slippery conditions for improved traction.

The Audi A6's Quattro 4WD system uses a Torsen differential to distribute power between the front and rear wheels. It has a 40:60 front-to-rear torque split for better handling and performance, but can also send up to 70% of the power to the front wheels or up to 85% to the rear wheels if needed. It also has an electronic differential lock to provide additional grip on slippery surfaces.