NC machining refers to machining performed by CNC machining tools. CNC index controlled machine tools are programmed and controlled by CNC machining language, usually G code. The NC machining G code language tells the NC machine tool which Cartesian position coordinates are used, and controls the tool feed speed and spindle speed, as well as functions such as tool converters and coolants. CNC machining has great advantages over manual machining. For example, parts produced by CNC machining are very accurate and repeatable; CNC machining can produce parts with complex shapes that cannot be completed by manual machining. CNC machining technology has now been widely popularized. Most machining workshops have CNC machining capabilities. The most common CNC machining methods in typical machining workshops are CNC milling, CNC turning, and CNC EDM wire cutting (EDM wire cutting).

The tools for CNC milling are called CNC milling machines or CNC machining centers. A lathe that performs CNC turning is called a CNC turning center. NC machining G code can be manually programmed, but usually the machining workshop uses CAM (Computer Aided Manufacturing) software to automatically read CAD (Computer Aided Design) files and generate G code programs to control CNC machine tools