An Assistant Referee is an official in sports, particularly in soccer, who helps the main referee make decisions during a game. They are positioned along the sidelines and use flags to signal when the ball goes out of play, when a player is offside, or to indicate fouls. Their role is crucial for ensuring fair play and maintaining the flow of the game. In addition to soccer, the term Assistant Referee can apply to other sports, such as American football and hockey, where officials assist the main referee in monitoring the game. Their collaboration helps improve the accuracy of calls and enhances the overall officiating process.