What's the difference in use between these synonims: official, umpire, a referee, judge (in reference to sports)?
Take a look at these pages which are wikipedia pages and perhaps not much easy to follow, but the advantage is that the first one has mentioned different terms used in different sports.
Referee - Wikipedia, the free encyclopedia
This one is just a short article about the difference between referee and umpire:
Difference Between Umpire and Referee | Difference Between | Umpire vs Referee