What are the differences between the Audi 80 and the A4?

I am considering buying an Audi but I am not sure what the main differences are between these two models. Can anyone explain?

The Audi 80 is a compact executive car produced from 1966 to 1996, while the A4 is a compact executive car since 1994. Both models have distinct features, but the A4 has been continuously updated with newer technology and design elements.

One major difference is that the Audi 80 has front-wheel drive, while the A4 has the option for front or all-wheel drive. This can make a difference in handling and performance, depending on your driving needs.