A fishing rod is a tool used to catch fish, usually for sport. (Sustenance and commercial fishing usually involves nets.) A length of fishing line is threaded along a long, flexible rod or pole; one end terminates in a barbed hook for catching the fish, while most of the rest of the line is wound around a reel at the base of the pole. The pulley-like arrangement of the reel allows the fish to be "reeled in" once caught. The use of a fishing rod is known as angling. Fishing rods vary in length and strain capabilities. Usually fishing rods will vary in size between 6 and 16 feet. This length advantage increaese the amount of force which the fish exerts on the fishermans arms.