What are the key differences between Audi's Quattro All-Wheel Drive and Four-Wheel Drive?

I've been researching Audi's different drivetrain options and I'm wondering what sets their Quattro All-Wheel Drive apart from their Four-Wheel Drive system. Are there any significant performance differences or is it just marketing?

Audi's Quattro All-Wheel Drive utilizes a torque-sensing center differential which constantly distributes power to each wheel based on traction needs, while Four-Wheel Drive typically uses a locked differential and relies on the driver to manually switch to all-wheel drive when needed.

Quattro All-Wheel Drive is a full-time system that continuously monitors and adjusts power distribution, while Four-Wheel Drive is typically only used in off-road or low-traction situations. So if you want all-weather and all-road capability, Quattro is the way to go.

The biggest difference between Quattro and Four-Wheel Drive is that Quattro is a proprietary system developed by Audi specifically for their vehicles, while Four-Wheel Drive is a more general term used for any vehicle with power going to all four wheels.