The EDM is a recently technology employed  to remove the  materials composed  of good conductors and essentially  metals, it  is based on controlling the erosive capacity of the electric discharges.
The machine tools able to performing this process are called "EDM machines"(Electrical Discharge Machining).
The EDM was discovered by the Mrs and Mr Lazarenko in 1943, he has had a strong impulse when the electronic technology has allowed its complete control.
Today the EDM, is mainly and effectively used in the production of molds (in particular molds for plastic components), particularly where the conventional milling technique is inadequate for carrying out particular narrow cavities.
The types of machines present on the market today are "die-sinking EDM", "wire WEDM" and EDM drilling machines.