CNC (Computer Numerically Controlled) Machining is a process of removing unwanted material from raw stock to produce a desired end product. This process is accomplished by utilizing a variety of tools, on multiple axis, being controlled by computer/program function. This results in the ability to make highly sophisticated shapes to extremely tight tolerances (+/-.0005) in a wide range of materials such as brass, aluminum, stainless steel, and plastics to name a few.
Sometimes, CNC machining is used in conjunction with casting as it is more economical to produce the rough geometry of a part using a casting method and then finish the product to exact specifications by CNC machining the rest.