A total of seven people control a GAA game. The match referee is assisted by two linesmen and four umpires.
The referee controls everything on the pitch, but the linesmen and umpires also do important jobs.
There are two umpires at each end of the pitch on either side of the goal and they decide if a score is made, the ball has crossed the end line for if a wide or a free is to be awarded.
They signal a score by waving a green flag for a goal or white flag for a point.
The linesmen operate on either side of the pitch and change sides at half-time.
They award sideline kicks or pucks, indicate to which side it's awarded and where it shall be taken.
If they spot any foul play on the pitch which they think hasn't been noticed by the referee, they can bring it to his attention at any time during the game.