What is the difference between the Audi 80 and 90?

I am looking to buy an Audi sedan, but I can't decide between the Audi 80 and 90 models. Can someone explain the main differences between the two?

The Audi 80 and 90 were two different generations of the Audi 80 series, with slight variations in styling and technology.

The Audi 90 was a higher-end model than the Audi 80, with more advanced features such as electronic stability control and a more powerful engine.

While the Audi 80 was produced from 1966 to 1996, the Audi 90 was only produced from 1985 to 1991.