What do the letters 'A1' stand for in Audi A1?

I've always been curious about the meaning behind Audi's model names, specifically the A1. Could you provide some insight into the reasoning behind this particular combination of letters and numbers?

The 'A' in the A1 represents Audi's core model line, while the '1' designates it as the smallest and most affordable model in that line.

Audi's naming convention is based on the engine's displacement in liters, so the 'A1' signifies that this particular model has a 1-liter engine.