In tennis, a Let (Let Service) occurs when a served ball touches the net but still lands in the correct service box. The point is replayed without penalty to the server.
Lets can also be called during a rally for unexpected distractions. These might include a ball from another court or a loud noise. The umpire or players can call a let.
There's no limit to how many Lets can happen in a row. Let calls ensure fairness in the game. They prevent points from being decided by lucky net cords or outside interference.