Hockey is any of a family of sports in which two teams compete by trying to maneuver a puck (a flat, 6 oz. rubber disc) or a hard ball into the opponents' goal, past the goaltender (often abbreviated goalie), using a stick.

The major forms of hockey are:

• Field hockey, that used to be played on grass with a ball but now is more frequently played on sand or water-based astroturf.
• Ice hockey, played on ice with a small rubber disc called a puck.
• Rink hockey, played indoors with a ball.

Field hockey and ice hockey both developed independently from an earlier form of the game. The dominant form in any region is usually referred to simply as hockey, with the less popular forms given more detailed names. In countries where field hockey is most popular, hockey is field hockey. Where ice hockey is played more commonly (especially Canada, the USA and Scandinavia), hockey on its own designates ice hockey. In south European countries (such as Spain, Portugal and Italy and certain South American countries especially Brazil and Argentina) hockey designates rink hockey.

Field hockey sticks are smaller than ice hockey sticks and have a hooked blade, whereas ice hockey sticks have a long blade that can lie flat on the playing surface when the stick is held upright. Rink hockey sticks have a curled "L" shape, and are about the same size of those in field hockey.

Other games are either derived from hockey or from hockey's predecessors:

• Bandy is played on ice with a ball on a football (soccer) size field, typically outdoors. It is in many ways field hockey played on ice.
• Floorball is played in sport halls.
• Roller hockey is a variant of ice hockey that is played on concrete or asphalt using in-line roller skates.
• Shinny is an informal version of ice hockey.
• Air hockey and table hockey are played on tables indoors.
• Underwater hockey is played on the bottom of a swimming pool.
• Street hockey is a version of ice hockey played (most typically) on residential streets with or without roller blades, on bare pavement. Games are usually informal with no referee and no set teams. Because the game is played in the middle of the road, it is often interrupted by traffic, at which point someone will yell "car" and players stand to the side of the road to allow the vehicle to pass.
• Ringette is an ice hockey variant that was designed for female players; it uses a straight stick and a rubber ring in place of a puck.
• Broomball is played on an ice hockey rink, but with a ball instead of a puck and a "broom" (actually a stick with a small plastic implement on the end) in place of the ice hockey stick.

Sometimes rink hockey is known as roller hockey, with roller hockey known as inline hockey.