The main job for the wide receiver is to catch the quarterback's pass. Wide receivers have to run fast. Most receivers are track runners. The wide receivers needs super speed and high grade hands. Wide receivers can score touchdowns two ways, catching the pass in the end zone or catching the pass, and then running into the end zone.
The defensive has two jobs, one to tackle the person that is running and sack the quarterback if it is a passing play. Defensive linemen are the first stopping point of the defense. If two people sack the quarterback both tacklers get a 1/2 a sack. Some teams have three men on the line, some have four. Speed and strength is very important to a defensive end because he must be able to fight off blocks. He must also be able to spin quickly away from the tackle's block or use his speed to go around him.