How does the Audi A7's Quattro system improve its handling in different road conditions?

I've read that the Audi A7 has Quattro all-wheel drive system. How exactly does this improve the car's handling in different road conditions like rain, snow, or gravel? Does it also make a difference in normal driving conditions?

The Quattro system in the Audi A7 uses sensors to constantly monitor the road surface and distribute power to the wheels that need it most. This improves traction and stability, especially in poor weather conditions.