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# Into to CNC Machining
Computer Numerical Control (CNC) machining is a manufacturing technique that uses computer software to control the movement of machinery and tools. This technology can manage a wide variety of advanced machines, including grinders, [lathes](/manufacturing-and-assembly/subtractive-manufacturing/lathes.md), [mills](/manufacturing-and-assembly/subtractive-manufacturing/cnc-mills.md), and CNC routers, enabling complex three-dimensional cutting operations with just one set of instructions.
Once a CNC system is started, the programmed instructions guide the tools and equipment to perform the required operations—similar to how a robot functions.
CNC programming involves a code generator that typically assumes the machines will operate without fault, although errors can increase when cutting in multiple directions at once. The positioning of each tool is determined by a sequence of commands known as the part program.
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Traditional numerical control machines received instructions via punch cards, while CNC machines use keyboards to input programs directly into a computer. These programs are stored digitally and can be written and modified by programmers. CNC systems offer greater computing power and flexibility, allowing updates or new commands to be added to existing programs through code revisions.
Additional CNC References
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