backspacing

[cm cows]

I havent really ever understood how the back spacing deal works. Right now I have a set of american eagle wheels that stick out way past my fenders. when i get a different set of wheels I dont want the wheels to stick out but i want them to be wide also. so can some one explain how the backspacing measurements work?

 

[j-rod]

Here's a good site that explains it:

https://www.rsracing.com/tech-wheel.html

 

[cm cows]

sweet thanks