What is an ace in tennis?

In tennis, an ace is a serve that is not touched by the receiver and lands in the service box. It's a point won directly by the server without the receiver making contact with the ball. Aces are highly valued because they are a direct display of the server's skill and power, preventing the opponent from even having a chance to return the ball. They are a crucial element in a player's strategy, particularly on the professional level, where high-speed serves and precise placement are common. A high ace count in a match often indicates a dominant performance.