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

I am looking to buy an Audi and considering the 80 and A4 models. Can someone explain the key technical differences between these two models? Are there any performance or feature upgrades worth noting?

The Audi 80 and A4 have many similarities, including body style and engine options. However, the A4 is newer and has more advanced technology and updated design elements. If you prioritize high-end features and modern design, the A4 may be a better choice for you.