CNC stands for computerized numerical control
CNC is an abbreviation for computerized numerical control. CNC is an electronic method to control and regulate machine tools called CNC machine, or the devices used in them such as controllers and computers.
Nearly every product will come into contact with machine tools at some point in the development process. Machine tools are machines that produce a product, part of a product or a form via machining, forming and removing material from raw parts.
From about 1960, the first numerical controls for machine tools were developed and built. Thanks to NC machines the demand for automobiles, airplanes and other consumer goods can be met, and quality standards upheld. From the mid-seventies NC became CNC – computerized numerical control.
CNC machines have been successfully used for decades
A CNC is not simply the connection of a computer to a machine tool, but a special customised computer solution on the application of the machine tool, which often has its own operating system and user interface. The use of computer technology in the field of machine tools significantly increases productivity; however it also creates new requests for machine builders, as well as for the users of machine tools. Depending on the type of production, the form of organisation, the expertise of the machine leader and the CNC used, there are various possibilities to equip a machine with a CNC program which is often used in parallel and integrated. No matter which programming principle is used in a company, a CNC program will always consist of geometry commands and the technological information. The programs are always structured in sets and many CNCs offer convenient ways to simulate the program before the start of the process and to assess if the expected piece will be created at the end.
You can find more information on CNC on Wikipedia: https://en.wikipedia.org/wiki/Numerical_control