The belts don't mean anything. The main purpose of a HW championship belt is to symbolize that you are the #1 guy. With so many "world championship" belts, the meaning has been lost, and when the belts don't symbolize anything than they are just there to look pretty.

It usually doesn't matter because in pretty much every division there is 1 guy that the majority of boxing fans believe is the #1. That means more than any belt.