In tennis, a double fault occurs when a server fails to land both of their service attempts in the appropriate area, resulting in a points loss. The server must hit the ball into the correct service box; if both attempts fail, the result is a double fault, and the opponent is awarded the point. This is typically a source of frustration for players, as it reflects a moment of service error. It underscores the importance of accuracy and consistency in serving, which is crucial for a successful game.