When a machine has its own independent computer control unit.
A computer-based motion control device programmable in a numerical word address format. A computer numerical control product typically includes a CPU section, operator interface devices, input/output signal and data devices, software and related peripheral apparatus.
CNC software provides a machine with instructions describing how to manufacture an item. This is similar to CAM but is specific to each machine. CNC machines are most often used for precision cutting, drilling, or shaping of metal products.