Which all-wheel-drive system is used in Audi's Quattro® technology?

I am trying to better understand the mechanics behind Audi's Quattro® all-wheel-drive system and which specific technology they use. My main goal is to improve my driving skills and make a more informed decision when purchasing a new Audi.

Audi's Quattro® technology is equipped with a traditional mechanical center differential which distributes power between the front and rear axles based on driving conditions.

The Quattro® technology in Audi's S4 models uses a crown-gear center differential with a torque vectoring function for better handling and performance.

For high-performance models like the Audi RS5, the Quattro® technology uses a rear-axle sport differential which actively distributes power between the rear wheels for improved cornering and stability.