What is advantage in in tennis?

Answer 1

An advantage is given to the player who wins a point at deuce (40:40.) If that player wins the next consecutive point after that they win that game. If the opposing player wins that point, the score goes back to deuce. A player must win two points consecutively at deuce in order to win the game.

Answer 2

When to score reaches 40-40 in an individual game of tennis, it is said that the score is at deuce. If the server scores the next point, they have advantage (ad in), which means if they score again they win that game. If the person who isn't serving scores at 40-40, they have the advantage (ad out), and if they score again they win that game. Advantage just means that whoever has it is one point away from winning a game that ties at 40-40.

It sounds so complicated, but it's really not XD. you just have to see it in action.