CNC precision machining is carried out by the use of computer numerical controlled machines. It refers to the automation of machine tools which are operated by programme commands, as opposed to manually controlled machines. CNC precision machining has been possible because of the first NC machines built in the 1940s and the 1950s and their modernization with the use of analogue and digital computers. CNC precision machining systems allow start to finish component design using highly automated CAD/CAM programs, which are used and interpreted by a computer to operate a particular machine. Many different types of machines and tools have CNC precision machining capabilities, and these can include drills, wood routers, water jet cutters, cylindrical grinders, lathes and milling machines.