A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A sheave or pulley wheel is a pulley using an axle supported by a frame or shell (block) to guide a cable or exert force. Pulley.
The function of a pulley is to lift heavy objects by changing the direction of the force on a flexible cable. It also consists a wheel with a groove in its outer edge and an axle. With the help of ropes, chains or cords, a pulley makes moving objects upward easier. Pulley reduces the force given to get the work done.