CNC machines can be combined into entire cells of tooling machines that can operate independently of each other. These automated features make it possible to produce thousands of parts with minimal supervision, and free the operator to perform other tasks.
The code used to program CNC units is generically called G-Code. It contains information about where parts of the machine should be positioned, and tells the machine exactly where to place a tool. Other instructions tell the machine additional details, like the speed a part should run at; how deep it should cut, burn, or punch; and the angle of an automated tool.