NC or “numerical control” machines are relatively speaking new mechanical tools programmed and encoded by software that began around the 1940s and 1950s. Existing machine tools were modified with motors moving specific controls to precisely follow coordinates fed into the system. Many of the early servomechanisms  became augmented with analog and later digital computers, eventually leading to the modern day CNC machine which stands for computer numerical control.
CNC machines are automated milling  tools that in turn create industrial components as detailed by a computer aided design without direct human intervention.

Today most CNC machines operate as milling machines, lathes, laser machine or even CNC grinders.    These machines work to quickly and  automatically engrave, route, or cut materials, including wood, plastics,  and other materials.   CNC machines used in major industry whether its for woodworking or metal can be sizeable (as many as 5 axis). Also, there are small CNC laser machines used by small businesses or hobbyists used for smaller design creatives.   CNC mechanical benefits include the fact that they can be used with various types of engravers or cutters such as those that utilize CO2 lasers, water, and even plasma.