What are some positions in the game of hockey?

Ice Hockey

Ice Hockey uses six players on ice at a time. These are usually the goalkeeper, two defensemen (normally left and right), a centreforward (or similar position) and two wing forwards.

Field Hockey has 11 players on the field at a time. These are usually the goalkeeper, two fullbacks (left and right, or forward and back), three halfbacks (left, centre and right), two wings/outer forwards, two inner forwards and a centreforward. Because of the number of players, many other formations and positions can be made to suit a team's needs.

In both variants, the goalkeeper may be replaced by another field/ice player at whim of the team. Ice hockey has rules regarding such a situation in regard to penalties and scoring; field hockey just plays as usual, with nobody receiving goalkeeping priveleges.