Computer Numerically Controlled milling (CNC), is the process of machining physical objects from 2d or 3d digital information. The process of CNC milling takes a 2-step procedure. The first step is the Tool path, the process of translating a 3D or 2D computer model into a series of 'paths' for the CNC mill bit to follow as it excavates the model from a block, bar, or plate of raw material. The second step of the procedure is the actual machining, which involves translating the tool paths into commands to small 'stepper' motors in the milling machine that move the head of mill incrementally in the X, Y and Z directions.