Computer Numerical Control (CNC) is one of the technologies used to control a machining operation via computer program. Most commonly used key computerized machine tools available in the industry are CNC Turning (Lathe) machine and CNC Milling machine. CNC helps to improve productivity by increasing the speed machine parts are produced, provides uniform quality across all products, better finishing by providing accuracy in dimensions, reduce complexity in manufacturing complex parts and reduce scrap. Drawback with CNC are huge initial investment and need for highly skilled operator to manage the system. Coordinate system is used for shaping metals, the cutting tool should move in contact with the work piece at certain specific points, while the work piece or cutting tool is rotating. Two types of Coordinate systems are Cartesian and Polar.