Mechanically speaking, there is no difference between an ATV and a "quad"—the terms are used interchangeably to describe four-wheeled off-road utility or sport vehicles equipped with low-pressure tires, straddle seating, and handlebar steering. "ATV" is the formal, technical designation standing for All-Terrain Vehicle, whereas "quad" is a popular colloquial nickname derived directly from the vehicle's four-wheel configuration, differentiating it from three-wheelers or side-by-side utility terrain vehicles (UTVs).