Here’s what Wikipedia has to say|
A CNC router is a computer controlled cutting machine related to the hand held router used for cutting various hard materials, such as wood, composites, aluminium, plastics, and foams. CNC stands for computer numerical control.
We have had our CNC router for a few years now. Ours, like the one in the following video, is an “E-Z Router”. We immediately named our little “robotic device” Marvin. He’s not really a robot, but it just seemed to fit! Marvin can accommodate materials up to 4′ x 8′ in size.
We have used Marvin to cut fancy shaped signs; make beautiful v-carved cedar cabin signs; produce stunning town entrance signs, and we even made 12″ nickels out of styrofoam! 
Boy, did they ever take a long time to router. Hmm… now we could make our nickels by using our laser engraver. His name is Helix.
