A Programmer Numerical Control plans numerical control program to control contour-path machining of parts on automatic machine tools; Computer Numerical Control (CNC) machines include, but are not limited to, machining tools such as lathes, multi-axis spindles, and milling machines, but the functions formerly performed by human operators are performed by a computer-control module; CNC machines cut away material from a solid block of metal, plastic, glass, or other materials to form a finished part.