In the early days, a hard-wired CNC system with fixed wiring was used, and a dedicated computer was used to control one device. Later, the use of a microcomputer instead of a dedicated computer, using different programming software to achieve different types of control, can enhance the system's control functions and flexibility, known as computer numerical control system (CNC) or cord CNC system. Later, it developed into a computer to directly manage and control a group of numerical control equipment, called computer group control system or direct numerical control system (DNC). Further developed into a network consisting of multiple CNC and NC devices and DNC computers to achieve multi-level control. In the 1980s, it developed into a group of machine tools and workpieces, tools, fixtures and automatic transmission lines, and was managed and controlled by computers to form a computer group control automatic line called Flexible Manufacturing System (FMS). The higher stage of the CNC system is the integration of mechanical design and manufacturing in the manufacturing industry, combining computer-aided design (CAD) with computer-aided manufacturing (CAM) to achieve a complete automation system for product design and manufacturing processes.
The early CNC system was composed of hardware circuits called Hardware NC. After the 1970s, the hardware circuit components were gradually replaced by special computers, which were called computer numerical control systems. Generally, they were equipped with special computers and equipped with interface circuits. It can realize the control of the movement of multiple numerical control devices. Therefore, the current numerical control is generally CNC (computer numerical control), and the concept of NC is rarely used again.