Usually special rules apply to the goalkeeper that do not hold for the other players. These rules are often instated to protect the goalkeeper, being an obvious target for dangerous or even violent actions. In addition, in certain sports like ice hockey, they are required to wear special equipment like heavy pads and a face mask to protect their bodies from impact from the play object like a puck.
In football, the goalkeeper defends their team's goal and has special privileges within the game. The goalkeeper may use their hands and arms to control the ball. Once a goalkeeper has picked up the ball or has two hands firmly on it the ball is out of play and the opposing team must leave the goal area. Play then recommences when the goalkeeper passes the ball to another member of his team or kicks the ball clear of the area.