Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a work piece. This may be done varying direction on one or several axes, cutter head speed, and pressure.

 Wire electrical discharge machining (EDM) is a process of metal machining in which a tool discharges thousands of sparks to a metal workpiece. … Instead of cutting the material, EDM melts or vaporizes it, leaving little debris and providing a very accurate line.