What does the Audi A7's 'Quattro' drivetrain mean?

I've heard that Audi has a unique drivetrain called 'Quattro'. What does this involve and what are the benefits?

The 'Quattro' drivetrain is Audi's all-wheel drive system, which distributes power to all four wheels for improved handling and traction. It uses a central differential to send power to the front and rear axles as needed. Some benefits of this system include improved stability, especially in adverse weather conditions, and enhanced cornering abilities.