What are the key features of Audi A3's quattro all-wheel drive?

I've been considering purchasing an Audi A3 and have heard about its quattro all-wheel drive system. Can someone provide more information on what this feature offers and how it differs from other AWD systems?

The quattro all-wheel drive in Audi A3 is a permanent system that provides power to all four wheels at all times, ensuring better traction and stability on any road surface. Compared to other AWD systems, it has a unique self-locking center differential that can send up to 70% of power to the front wheels or up to 85% to the rear wheels if necessary.