Ice hockey is considered the fastest sport in the world and such as, new players when trying to understand the game they have a really bad time to understand what happens in each moment and why there are so many interruptions.
Ice hockey matches consist of three 20 minute periods with a 15 minute rest period between them. Time will only be in motion when the puck is too, so any interruption, foul or goal will cause it to stop. Each team has the possibility to make a timeout in each match.
In the case of a tie at the end of the three periods, an extra time (Over Time) will be played that lasts 5 minutes. As in football with the golden goal, the team that scores take the game. In the NHL 3 vs 3 is played and in Europe 4 vs 4. If there is no tiebreaker in the OT there will be penalties.
According to international regulations in the field, there may be 20 skaters and 2 goalkeepers while in the NHL it is reduced to 18 in the field, between attackers and defenders, and two goalkeepers. There can be no more than six players on the court, usually 5 + 1, and there are no limitations on the changes.