Ice hockey is very well-known and well-liked in Canada, Russia, Sweden, Finland, the Czech Republic, the United States, Latvia and Slovakia. Most of the best players in the world play in the National Hockey League (NHL), which has 31 teams in the United States and Canada. These teams are divided 2 conferences and 4 divisions. In the regular season, they play 82 games. Each team faces each other about 3 times. They try to win the Stanley Cup at the end of the year. Another popular hockey league is the Kontinental Hockey League (KHL), which has teams in Russia, Kazakhstan, Latvia, Belarus, Slovakia, China and Croatia. In North America, women play in the Canadian Women's Hockey League and the Western Women's Hockey League. In North America and Europe, men's hockey is much more popular than women's hockey. Hockey is played by both men and women at the Olympic games, and at world championships. Ice hockey began in Canada in the 19th century. There are two types of penalty: The major and the minor. The minor is the main one the referee will call during a game and the players have to go in the penalty box for two minutes. The major is when players fight with each other or when someone did something very dangerous. Most of time players are kicked out of the games but in a fight they only get 5 minutes in the penalty box. In the National Hockey League (NHL) there are four referees. Two lineman and two head referee. Only head referees can call the penalty. They can be recognized by the orange armband on their arm. In the major league, the game is separated into three periods of 20 minutes. For the minor league, the time can be different for each category. Each period starts after the face-off. A face-off is when two teams are in position around the face-off circle. Then, the referee drops the puck between the players who play center. There are 6 different positions: center, right wing, left wing, right defense, left defense and goalie. The play is over after a whistle of any referee. After a whistle-blow, the time stops running. Each team can have a maximum of 20 players, including two goaltenders who have a zone to defend. Each team has one captain and two or three assistant captains. The ice is separated into three zones. Each zone is marked by lines. The center zone is between two blue lines and team zones are between one blue line and the end of the ice. The lineman can whistle for two reasons: icing and offside. An icing is when a player throws the puck into the zone before he crosses the red line (center line) and an offside is when a player enters the zone before the one who has the puck enters with it. 