What kind of warranty does Audi offer for their vehicles?

I am interested in purchasing an Audi but want to make sure I understand their warranty coverage. Can you provide more details on what their warranty covers and for how long?

Audi offers a limited warranty on all their vehicles that covers four years or 50,000 miles, whichever comes first.

Additionally, they have a powertrain warranty that covers five years or 50,000 miles, also whichever comes first.

Their corrosion perforation warranty covers 12 years, unlimited mileage.