What is the difference between Audi A1 S line and S1?

I'm confused by the names, they sound similar but I feel like they're different models. Can someone clarify?

The Audi A1 S line is a trim level available on multiple Audi models, including the A1. The S1, on the other hand, is a separate model that is a performance variant of the A1. It typically has a more powerful engine and upgraded features, such as larger brakes and a sportier suspension.

Think of it like this: the Audi A1 S line is like getting a fancier version of a car, while the S1 is like getting a sportier version of the A1 specifically.

Just to confuse things further - the trim levels for the A1 S line can vary between countries, so what's available on an A1 S line in one country may not be the same in another. However, the S1 will always be a separate model.