Each position has a different role on the ice and set of responsibilities. The forwards (center and wingers) are attacking positions and have a goal of shooting on the other team's goal. The defensemen help the goalie by preventing players on the other team from entering the defensive zone. The goalie is the last line of defense for stopping goals from going into the net.
A center's role is often as the best defensive forward on the line. Center's are responsible for taking faceoffs at the various face-off circles around the ice and helping to patrol the defensive zone.
A right winger's role is to line up on the right side of a center during a faceoff. A right winger is responsible for patrolling the right side of the ice in the defensive zone, and to keep an eye on the opposing team's left defender.
The role of the left defenseman is to patrol the left side of the ice and serve as the last line of defense from the other team scoring a goal.
There are two team captains on a hockey team called the captain and alternate captain. The captain wears the letter "C" on the jersey. The alternate captain wears the letter "A" on the jersey. The captain of the team is responsible for interpreting the rules of the game and discussing calls with the referee if there is a disagreement.
Team captains can not be goalies. If the captain is in the penalty box, unable to play, or not on the ice the alternate captain is in charge. Teams can have two or three alternate captains if the captain is not in the game.
When a team is on offense, all of their players are working together to score a goal. They do this by keeping control of the puck in the offensive zone.
When on defense, the players on the team are helping the goalie by keeping the puck out of the defensive zone. They are also trying to force a turnover by checking, intercepting, and blocking shots on goal.
The goalie blocks shots on goal and defends against scores. The center takes faceoffs and makes shots on goal. The wingers help the center to make goals. The defensemen stay in the defensive zone and help defend against shots on their team's goal.
Yes, these are called line changes. Throughout a hockey game, players go to the bench and another set of players take their place on the ice. Line changes can happen at any time in a game.
All positions in hockey are worth exploring and trying out. As a center, you get to take faceoffs. As a winger you'll have the chance to score a lot of goals. If you choose to play defenseman you'll be making lots of passes and blocking shots on goal. Finally, as a goalie you'll have all the pressure on you to stop shots by opposing players. This is one of the hardest positions to play and the blame can often rest on the goalie.
A hockey team has 20 players dressed for a game: 12 forwards, six defenders, and two goalies. It's important to have substitutes because players fatigue quickly, and typically only stay on the ice for about 45 seconds at a time.