What is the difference between AC and DC fast charging for the Audi e-Tron?

I'm interested in fast charging options for my Audi e-Tron, but I'm confused about the difference between AC and DC. Can someone explain the technical aspects of each type of fast charging and how they affect charging times?

AC charging uses a converter to convert AC power to DC for your car's battery, while DC charging directly provides DC power. In terms of efficiency, DC charging is faster and more efficient for electric vehicle charging.

DC fast charging is generally more expensive than AC charging, as it requires specialized equipment and infrastructure. However, the added cost may be worth it for the convenience and faster charging times.