This is used to fake out the defense. He sees that a different play will work better. A player is moving parallel to the line of scrimmage to get open or to get to a place. Only one player can be in motion and cannot turn up field until the ball is snapped. If they do it is illegal motion .
Teams call time out when they are confused on what play to run or if they have trouble with a play.
The positioning of the eleven players. Both the offense and defense have formations. These formations tell the players when to go before a play start. See different formations . When two receivers cross and one bumps the defender of the other.