A pulley is a simple machine that consists of a wheel on an axle or shaft designed to support movement and change the direction of force. It is commonly used to lift heavy objects by using a rope or cable that runs over the wheel. Pulleys can be found in various applications, such as cranes, elevators, and flagpoles. Pulleys can be used individually or in combination to create a pulley system, which makes lifting easier by distributing the weight of the load. This system can reduce the amount of force needed to lift an object, making it more efficient. Pulleys are essential in construction, shipping, and many other industries.