Tennis is a sport played between either two players (”Singles”) or two teams of two players (”doubles”). Players use a stringed racquet to strike a hollow rubber ball covered with felt over a net into the opponent’s court.

Tennis is now an Olympic sport and is played at all levels of society, by all ages, and in many countries around the world. Except for the adoption of the tie-breaker in the 1970s, its rules have remained remarkably unchanged since the 1890s.

There are four types of tennis courts; clay, hard-court, grass, and indoor (wood, carpet).

Some players are more successful on certain surfaces and are known as, for instance, “clay court specialists” such as Rafael Nadal.

Grass is a fast surface and was the surface used at three of the Grand Slam tournaments until the Australian Open and the U.S. Open changed to hard-court.

The players (or teams) start on opposite sides of the net. One player is designated the server, and the opposing player, or in doubles one of the opposing players, is the receiver. Service alternates between the two halves of the court.

A tennis match usually comprises best of three sets (women’s) or best of five sets (men’s). A set consists of a number of games, and games, in turn, consist of points.

In serious play, there is an officiating chair umpire (usually referred to as the umpire), who sits in a raised chair to one side of the court. The umpire has absolute authority to make factual determinations.