They are skilled at catching a high punt or kickoff with three or four players ready to tackle them. If a punt is high and the returner does not want to run with the ball he calls for a fair catch . On kickoffs teams form a wedge to block for the returner. Having a good return team can get to good field position and have less distance to go to score a touchdown. In the 1997 Super Bowl Green Bay Packer Desmond Howard was the MVP due to his returns and the only special team player ever to win that award.
Teams also have to cover kicks and punts.
These players run down the field and try to tackle the receiver. Teams have a specific player a gunner that tries to get to the receiver first and stop him form running with the ball. Having a good punter that kicks the ball high and deep can keep the other team far from the endzone. Special Teams plays .