How does the all-wheel drive system work in the Audi A3?

I'm considering purchasing an Audi A3 but I am curious about the all-wheel drive system. Can you explain how it works and if it makes a significant difference in the driving experience?

The Audi A3 uses a restyled version of its Quattro all-wheel drive system that operates as a front-wheel drive until wheel sensors detect slippage, at which point power is automatically transferred to the rear wheels. This provides enhanced traction and stability in all driving conditions.

I own an Audi A3 and the all-wheel drive system makes a huge difference in the winter. I feel much more confident driving in snowy and icy conditions compared to my previous vehicles. It's definitely worth the extra cost.