I. CNC Drilling In the case of CNC drilling, the CNC machine usually advances the rotary drill bit perpendicular to the plane of the workpiece surface. This technique produces vertically aligned holes. Their diameter is equal to the diameter of the drill bit used for drilling. The operational capabilities of the drilling process include counterboring, milling, reaming, and tapping.II. CNC Milling During CNC milling, the CNC machine feeds the workpiece to the cutting tool in the same direction as the rotation of the tool. This is not the case with manual milling. Here, the machine feeds the workpiece in the opposite direction to the rotation of the cutting tool. The operational capabilities of the milling process include : face milling: cutting flat, shallow surfaces and flat-bottomed cavities in the workpiece; Peripheral milling: cutting deep cavities in the workpiece, such as slots and threads.III. CNC Turning In CNC turning, the CNC machine feeds the cutting tool in a linear motion along the surface of the rotating workpiece. This removes material around the circumference until the desired diameter is reached. This technique makes it possible to shape cylindrical parts with external and internal features such as slots, cones, and threads. The operational capabilities of the turning process include boring, facing, grooving, and threading.IV. Electrical Discharge Machining (EDM)  Electroerosion machining (EDM) is a process that consists of molding parts of a particular shape with electric sparks. In this case, current discharges occur between two electrodes, allowing sections of a given part to be removed. When the space between the electrodes becomes smaller, the electric field becomes stronger than the dielectric. This causes a current to flow between the two electrodes. As a result, each one ejects parts of a workpiece.In a process called "rinsing," a liquid dielectric appears when the current between the two electrodes has stopped. This then carries away debris from each finished part.