CNC stands for “computer numerical control” and refers to the use of computer technology to control machine tools, such as lathes, mills, and routers. NC, or “numerical control,” is the earlier version of this technology, in which the control commands were input manually via punch cards or other means, rather than through a computer. In CNC technology, a computer program is used to control the machine tool, allowing for automation, precision, and flexibility in the manufacturing process.