In [[sport]]s, the '''ball''' is a spherical (or ellipsoid, as in [[rugby]] and American [[football]]) shape that is used in some fashion for play. They can range in size from a half inch or so for marbles, to beach balls several feet in diameter. Materials also vary, again from the hard [[glass]] used in marbles, through many that are created out of natural materials like [[leather]] with an inflatable [[bladder]], to simple hollow [[plastic]] [[sphere]]s or molded foam. | In [[sport]]s, the '''ball''' is a spherical (or ellipsoid, as in [[rugby]] and American [[football]]) shape that is used in some fashion for play. They can range in size from a half inch or so for marbles, to beach balls several feet in diameter. Materials also vary, again from the hard [[glass]] used in marbles, through many that are created out of natural materials like [[leather]] with an inflatable [[bladder]], to simple hollow [[plastic]] [[sphere]]s or molded foam. |