A pulley system is a simple machine that helps lift heavy objects with less effort. It consists of a wheel with a groove around its edge, through which a rope or cable runs. When you pull down on one side of the rope, the wheel turns, allowing you to lift the object on the other side. This makes it easier to move things like heavy boxes or construction materials. Pulleys can be used alone or combined in a series to create a more complex system. For example, a block and tackle system uses multiple pulleys to reduce the amount of force needed to lift an object, making it even easier to handle heavy loads.