A Line Judge in tennis is an official who watches specific lines on the court.
They call whether balls land in or out during play. Line judges sit or stand at the edges of the tennis court. They make quick decisions about where the ball lands. Their calls can be overruled by the chair umpire if needed.
Line judges also watch for foot faults during serves. They use hand signals and voice calls to communicate their decisions. Line judges are important for fair play in tennis matches.
In recent years, some tournaments have started using electronic systems instead of line judges.