NC (Numerical Control) machining uses punched tapes or fixed programs to control machine movements. It has limited flexibility and requires manual intervention to change machining instructions.
CNC (Computer Numerical Control) machining uses a computer to store, edit, and execute machining programs. It allows higher accuracy, faster setup, and better repeatability, making CNC machining the standard for modern precision manufacturing.
DNC (Direct Numerical Control) machining connects multiple CNC machines to a central computer system. Programs are sent, updated, and monitored in real time, which is ideal for high-mix, multi-machine production environments.