What is the difference between Shelbyville and Springfield?

A asked:

What Simpsons episodes feature them?
Why are they at each others throats?

What is getting said here?
Fantastic triangle of responses.

VERISSIMO

Where can I find a video clip from the Simpson episode “22 Short Films about Springfield?”?

Guppie asked:

I just want the part with Nelson laughing at the very tall man in the little car. I can’t find it anywhere!

NEASON