Relative to the side, to the side, to what does not come from a straight or direct line but adjacent. In sports it is said of the player who moves on the left or right sides of a court.
Relative to one side , relative to one side . In the game of some sports, it is the player who acts by the bands or sides. Acting on the end.
In football, a player who carries out his activity on one side of the field. Its main mission is to contain the advances of the opposing team by that band, although it can also do offensive tasks.