Objects

smooth underside or a separate body supported by two or more smooth, relatively narrow, longitudinal runners similar in principle to skis. This reduces the amount of friction, which helps to carry heavy loads. Some designs are used to transport passengers or cargo across relatively level ground. Others are designed to go downhill for recreation, particularly by children, or competition. (Compare cross-country skiing with its downhill cousin.) Shades of meaning differentiating the three terms often reflect regional variations depending on historical uses and prevailing climate.