In tennis, a serve that goes untouched by the receiver is referred to as an ace. An ace occurs when a player serves the ball in such a way that the opponent cannot return it, resulting in an immediate point for the server. Aces are highly regarded in the sport, often showcasing a player's serve speed, precision, and ability to outsmart their opponent. Players who frequently hit aces emphasize their serving skills, which can be a significant advantage in matches and tournaments.