What is Pulley?

A pulley is one of the six basic simple machines. The purpose of a pulley is to change the direction of an applied force. For example, you hold one end of a rope, a box is attached to the other end of a rope which is fed through a pulley. Rather than having to push up on the box to move it higher, you can simply pull down on the rope to raise the box. You can find more information here: