Tennis is a sport played between either two players (singles) or two teams of two players each (doubles). Players use a stringed racquet to strike a ball, a hollow rubber sphere covered in felt, over a net into the opponent's court. Tennis used to be called lawn tennis to distinguish it from its predecessor real tennis (also known as royal tennis, court tennis or jeu de paume), a form of the game played indoors on a different kind of a court. Originating in England in the late 19th century, the game spread first throughout the English-speaking world, particularly among the upper classes. Tennis is played in the Summer Olympic Games and at all levels of society, by individuals of all ages many countries around the world. Its rules have remained largely unchanged since the 1890s. Along with its millions of players, tennis claims millions of people who follow the sport as spectators, being particularly interested in the four Grand Slam tournaments.
