Skateboards are composed of several parts. The deck forms the body of the skateboard and provides a place to stand. It is covered with grip tape, which adds friction to its surface. The deck is normally 76–91 cm long (2 1/2 to 3 feet). The longboard, a common variant of the skateboard, has a longer deck. Decks were originally a single piece of wood but are now more commonly made of composite materials. Attached to the deck are two metal trucks, which connect to the wheels. (The corresponding parts of trains and other vehicles are also called trucks.) The trucks are further composed of two parts. The top part of the truck is screwed to the deck and is called the baseplate, and beneath it is the hanger. Between the baseplate and the hanger are bushings, also rubbers or grommets, that provide the spring mechanism for turning the skateboard. A bolt called a kingpin holds these parts together. Two polyurethane wheels attach to each hanger. Inside the wheels are bearings.
Skateboards are used for skateboarding and skateboarding tricks. A person who rides a skateboard is a skateboarder or a skater. Skateboarders sometimes wear helmets, knee and elbow pads, wrist braces, or other safety equipment, especially when riding in skate parks.