Here, the names of the players and their functions are explained in a way that even I can understand. The players are like chess pieces with shoulder pads. Every position has its function and its general set of movements. On the offensive side (the one with the ball trying to make it ten yards down the field), the quarterback is the king; his guards and tackles protect him on either side like knights and rooks. The linemen in front of him are pawns. The defensive side has a completely different set of players: defensive linemen, linebackers, and defensive backs. Their job is merely to stop the other side from moving or throwing the ball.