The pulley is a simple machine that combines the use of a rope and an indented wheel to raise and lower heavy objects. One end of the rope is attached to the object you want to move. The rope is put into the indentation in the side of the wheel. As the other end of the rope is pulled on, the wheel rotates, and the object moves. They can allow you to move objects sideways as well as up and down.

Some examples of pulleys are Venetian blind ropes and pulled clothes lines.

The five most simple machines are the wheel, the pulley, the inclined plane, the lever and the wedge .

A simple machine helps make work easier. It can also make it easier to move objects. They use energy to work and have few or no moving parts.