How does the Audi A8 Lane Assist feature work?

I've heard that the Audi A8 has a Lane Assist feature, but how does it actually function? Can it detect when I drift out of my lane and correct my steering? Or is it just a warning system?

The Audi A8 Lane Assist feature uses a camera to detect lane markings and can actively steer the vehicle back into the correct lane if it detects drifting. It can also provide visual and audible alerts if you're unintentionally leaving your lane.