What are the biggest differences between the Audi A4 and A6?

I'm considering buying a new Audi and I'm torn between the A4 and A6. I know they're both great cars, but I want to know the key differences between them before making a decision.

The biggest difference between the Audi A4 and A6 is in their size and price point. The A4 is smaller and more affordable, while the A6 offers more space and luxury features.

Another major difference is the engine options available in each car. The A4 has a more fuel-efficient and smaller engine, while the A6 offers more powerful and larger engine options.