Serve

A serve (or, more formally, a service) in tennis is a shot to start a point. The serve is initiated by tossing the ball into the air and hitting it (usually near the apex of its trajectory) into the diagonally opposite service box without touching the net. The server may employ different types of serve: a flat, a top-spin, an American twist (or kick), or a slice serve. A severely sliced serve is sometimes called a sidespin. Some servers are content to use the serve simply to initiate the point; advanced players often try to hit a winning shot with their serve. A winning serve that is not touched by the opponent is called an ace.