What is the key difference between the Audi A3 and A4 models?

I am considering purchasing an Audi and I am wondering what sets the A3 and A4 models apart from each other in terms of performance and features.

The main difference between the Audi A3 and A4 models lies in their size and engine options. The A3 is a compact car while the A4 is mid-size. The A3 also offers a smaller engine with a turbocharged 4-cylinder, while the A4 has more powerful options including a V6 engine.

Besides the size and engine variations, there are also differences in the interior features between the A3 and A4. While both models offer high-quality materials and advanced technology, the A4 has a more spacious and upscale cabin with additional features such as a virtual cockpit display.