What are the key features of the Audi A6's quattro four-wheel drive system?

I've been researching different car models and have heard good things about Audi's quattro four-wheel drive system. Can you please provide a detailed explanation of its features and advantages?

The quattro four-wheel drive system in the Audi A6 is renowned for its superior handling and traction control. It uses a center differential to distribute power between the front and rear wheels, allowing for optimal grip and stability. It also has the ability to send up to 85% of power to the rear wheels in case of loss of traction on the front. This is especially useful for driving in inclement weather or on uneven terrain.