Computer Numerical Control (CNC) machining refers to controlling machining tools (such as lathes, mills, 3D printers and cutting machines) through the use of a computer that defines numerical parameters for the operation to be performed.
CNC machining involves processing a material to meet precise specifications. This is done by a computer that contains coded programmed instructions for how the operation is to be performed and that controls the machine that actually performs the task. A CNC machine is typically a motorized tool that is fully maneuverable and that is also mounted on a fully maneuverable platform, giving it the ability to operate in 3 dimensions on a given material. These systems are much more precise than the previous methods for machining which required manual control and the use of pre-fabricated patterns. Today the shape and dimensions required are created in computer aided design (CAD) programs and then uploaded to the CNC machine which produces them to extremely high tolerances.