There are several different sports referred to as "hockey," including field hockey, ice hockey, and roller hockey. The most popular version depends on the region. In North America, the term usually refers to ice hockey, while in Europe and other parts of the world, it often means field hockey. 

Ice Hockey

Ice hockey is a contact team sport played on ice skates, usually on an ice skating rink. 

• Object: Propel a vulcanized rubber puck into the opponent's net with a hockey stick.

• Teams: Typically six players per side (three forwards, two defencemen, and one goaltender).

• Periods: A standard professional game consists of three 20-minute periods.

• Leagues: The National Hockey League (NHL) is the most prominent professional league.

• Origins: The modern game of ice hockey was developed in Canada. 

Field Hockey

Field hockey is a stick-and-ball sport played on a grass or turf field. 

• Object: Hit a hard ball into the opposing team's goal with a hooked stick.

• Teams: Two teams of 11 players compete against each other.

• Periods: A match is composed of four 15-minute quarters.

• Governing Body: The International Hockey Federation (FIH) governs the sport worldwide.

• History: A form of the game has existed for thousands of years, but the modern version emerged in mid-19th century England. 

Other variations

• Roller Hockey: Played on a dry rink with players wearing roller skates or inline skates. Teams hit either a puck or a ball.

• Street Hockey: A dry-land variant played on a hard surface, often using a ball instead of a puck.

• Bandy: Played with a ball on a large ice surface, with many rules similar to soccer. It is primarily played in Russia and Sweden.