What is car mileage, and how do i know if it is good or not?

I went on cars.com to find some used cars just to get a general idea of what i want to buy. for each car, theres the mileage that goes with it.

for example, i looked up a 2001 audi TT roadster and its mileage is about 75,000 miles. is that really bad??

i dont really understand what mileage is and how to determine if it is good or not. help please?

Average is around 12,000 a year.

So, it's really easy.

Multiple 12,000 by how many years old the car is.

In this case, it's 84,000. Then compare to the miles you have, which is 75,000.

So, it's about 9,000 miles below average.

Which means it's perfectly fine.