What is Audi A3’s Quattro all-wheel drive system and how does it work?

Could you please provide a technical explanation of the Audi A3's Quattro all-wheel drive system and how it differs from traditional front-wheel and rear-wheel drive systems?

The Quattro all-wheel drive system on the Audi A3 is a permanent, electronically controlled system that distributes power between the front and rear axles according to driving conditions. In normal conditions, it sends 60% of the power to the front wheels and 40% to the rear wheels, providing a balanced and responsive driving experience. It also has a self-locking centre differential and electronic torque vectoring for optimal handling in different driving situations.