Tennis judges, also known as umpires, are responsible for officiating tennis matches. They make sure that the rules of the game are followed and that the match is conducted fairly. Umpires also have the authority to make decisions on the court, such as awarding points or deciding when a ball is out of bounds. Umpires must be knowledgeable about the rules of the game and must be able to make quick decisions in order to ensure the match runs smoothly.