Our FabLab is currently equipped three different CNC (computer numerical control) machines, and they all work similarly: three motors move a drill bit along 3 axes (left/right, front/back, up/down) according to instructions sent to it by the computer. These machines can be used for a wide range of projects, from cutting your name into a 2x4, making molds for resin or latex, and even cutting away copper to form the traces of a circuitboard!
An introduction to using the Roland Modela milling machine can be viewed here. http://youtu.be/RpJ0vfDV71c