Tennis is a racquet sport that can be played individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a racquet that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The object of the game is to play the ball in such a way that the opponent is not able to play a good return. The opponent who is unable to return the ball will not gain a point, while the opposite opponent will. More: en.wikipedia.org.