Why is the Audi A5's Quattro system unique and what benefits does it provide?

I've heard about the Quattro system in Audi A5 but I don't understand why it's so special. Can somebody explain the technical details and advantages of this feature?

The Quattro system in Audi A5 is a permanent all-wheel drive system that distributes power to all four wheels for improved traction and handling. It also provides better stability and control, especially in challenging driving conditions.

With the Quattro system, Audi A5 can transfer up to 70% of its power to the front wheels and up to 85% to the rear wheels, allowing for a more dynamic driving experience. It also offers better fuel efficiency compared to traditional all-wheel drive systems.