Field hockey, or hockey, is a team sport in which a team of players attempts to score goals by hitting, pushing or flicking a ball into an opposing team's goal using sticks. It is most commonly known simply as "hockey"; however, the name field hockey is used in countries in which the word hockey is generally reserved for another form of hockey, such as ice hockey or street hockey. Hockey has several regular international tournaments for both men and women. These include the Olympic Games, the Commonwealth Games, the quadrennial Hockey World Cups, the annual Champions Trophies and World Cups for juniors. The International Hockey Federation (FIH) is the global governing body. It organizes events such as the Hockey World Cup and Women's Hockey World Cup. The Hockey Rules Board under FIH produces rules for the sport. Many countries have extensive club competitions for junior and senior players. Despite the large number of participants—hockey is thought to be the field team sport with the third largest number of participants worldwide (the first being association football and second being Cricket)—club hockey is not a popular spectator sport and few players play as full-time professionals. Hockey is a sport played internationally by both males and females. In countries where winter prevents play outdoors, hockey is played indoors during the off-season. This variant, indoor field hockey, differs in a number of respects. For example, it is 6-a-side rather than 11, the field is reduced to approximately 40 m x 20 m; the shooting circles are 9m; players may not raise the ball outside the circle nor hit it. The sidelines are replaced with barriers to rebound the ball.