What is a screw?

A screw is a rod with an inclined plane wrapped around it.

The spiraling inclined plane forms ridges which are called threads.

Some screws move objects along the threads while others twist in a spiraling motion to move different materials.

Screws can change the amount of force needed to do a job.

Screws can also change the distance over which the force is applied.

Real life examples of screws.