What's the difference between the Audi A3 and A4 models?

I'm interested in purchasing an Audi but I'm not sure what the main differences are between the A3 and A4 models. Can you provide some insight?

The biggest difference between the Audi A3 and A4 models is their size. The A4 is a larger sedan, making it more spacious and comfortable for passengers. The A3, on the other hand, is a smaller, sportier option.

One major difference between the A3 and A4 is in their engines. The A3 has a more powerful turbocharged engine, while the A4 has a more fuel-efficient option. It depends on your priorities in terms of performance versus fuel economy.