In modern CNC systems, end-to-end component design is highly automated using CAD/CAM programs. The programs produce a computer file that is interpreted to extract the commands needed to operate a particular machine, and then loaded into the CNC machines for production.
G-code is the most common method of programming.
Modern CNC mills consist of a table that moves in the X and Y axes and a tool spindle that moves in the Z (depth). The position of the tool is driven by motors through a series of step-down gears in order to provide highly accurate movements, or in modern designs, direct-drive stepper motors.
Our company uses SolidWorks as our main CAD program and Power Mill as our CAM program.