Skateboarding is a popular sport and form of recreation in which an individual rides a small, narrow board mounted on four wheels, called a skateboard. The skateboarder balances on top of the deck (board) in the manner of riding a snowboard or a surfboard. Skateboarding is most popular among boys and young men. Professional skateboarders perform in competitions that are held on specially constructed ramps, or they race on the street. Some people use skateboards for transportation.