Part of tennis' allure is its rules have changed little since the game was invented in the late 19th century in the United Kingdom. The two main variations of tennis are singles and doubles. In singles, players compete one-on-one. In doubles, teams of two players each face off.

Another reason for the sport's popularity is the few pieces of tennis equipment needed to play. Along with a tennis court – which can be found in most public parks and consists of asphalt or concrete (called hardcourts), clay, or grass surfaces – all a player needs is a tennis ball and a tennis racket. Once made of wood, tennis rackets frames are made today from composite materials. Millions are spent each year on tennis rackets, tennis balls and tennis shoes.

Professional tennis matches draw huge crowds courtside and on television. The biggest of them all, Wimbledon, is held in England each summer. One of the four “Grand Slam” events, winning at Wimbledon is akin to a football player being on a Super Bowl winning team. First held in 1877, Wimbledon is the oldest tennis championship in the world. Other events in the grand slam are tennis open events considered to be the national championships of the United States, France, and Australia: The U.S. Open, the French Open, and the Australian Open. The International Tennis Federation oversees professional tennis, and the sport is one of the most followed of all professional sports.