What does man in motion mean in football?

Answer 1

If a running back, wide receiver, or a tight end are originally set in one spot and begins to run to the opposite side of the formation, even though they may not go all the way to the opposite side. In American 11-msn football, only one player may be in motion at a time when the ball is snapped, and he must be running parallel to the line of scrimmage or away from it. Two players may be in motion at the same time, but they both must come set before the snap or another player goes in motion. In Canadian 12-man or Indoor 8-man football, two players can be in motion at the time of the snap, and they can go in any direction they like as long as they are behind the line of scrimmage at the time of the snap.