A screw is a kind of inclined plane wrapped around a cylinder. Compare a screw to an inclined plane and you will see the similarities as the thread on a screw advances upward to its head.

Screws are very useful to holds things together. For example goldminers use normal size screws to hold things like rocker boxes, sluice boxes, and wagons together. Goldminers also have machines with enormous screw shaped diggers called augers that are used to break up the ground. The screw is a very useful tool. Almost everything we have contains a screw.