Tennis originated in Britain in the late 19th century as "lawn tennis" to differentiate it from "real tennis" which was played indoors. Lawn tennis spread among the upper classes in England and then worldwide. Tennis can be played by anyone with a racquet and is popular as both a participant and spectator sport, especially the four Grand Slam tournaments: the Australian Open, French Open, Wimbledon, and US Open. Tennis matches are typically best of three or five sets, with sets made up of games and points to win games and ultimately the set.