What is the difference between Audi's quattro and e-tron models?

I am looking to purchase an Audi and I'm a bit confused about the different model designations. Can you explain the differences between the quattro and e-tron models and which one would be better for my needs?

Audi's quattro models refer to their all-wheel drive system, which is available on most of their vehicles. This provides better traction and handling, especially in adverse weather conditions. The e-tron models, on the other hand, refer to their line of fully electric vehicles. These models have the added benefit of no emissions and lower operating costs.