Surface grinding is used to produce a smooth finish on flat surfaces, is a widely used abrasive machining process in which a spinning wheel covered in rough particles (grinding wheel) cuts chips of metallic or nonmetallic substance from a workpiece, making a face of it flat or smooth.
CNC grinding is the same as surface or OD grinding except the machine is controlled by a computer and a computer program instead or manual controls.
O.D Grinding is an abrasive machining process that uses a grinding wheel as the cutting tool on the outside diameter of cylindrical work piece to grind to precise dimensions
CNC turning is a computer controlled process on a computer controlled lathe tool machine. The machine is controlled by a computer and a computer program that is programed to the part dimensions from the part blueprint.