Can be thought of as an inclined plane wrapped around a cylinder. This spiral inclined plane forms the threads of the screw.
When you twist a screw into a piece of wood, you exert an input force on the screw. The threads of a screw act like an inclined plane to increase the distance over which you exert the input force. As the threads of screw turn, they exert an output force on the wood, pulling the screw into the wood. Friction between the screw and wood holds screw in place.
Ex: Bolts, light bulbs, Jar lids