Without the ref or umpire, there is no game. Without the judge or the timekeeper, there is no tournament.
These people are the technical officials on the field or court making sure that there is safe and fair competition and helping the players to enjoy their sport.
Many officials start when they are encouraged to help out at their local club. Clubs should put their officials in touch with the National Governing Body so that they can sign up to a suitable training course and receive the guidance they need should they wish to progress their officiating.