The current produced in an electrochemical cell when corrosion occurs is known as the corrosion current. The flow of electrons from the anode (oxidation region on the surface) to the cathode (reduction region at inner layers) is referred to as electrochemical corrosion. An electric current is generated in the system by passaging electrons from the electronegative to the more electropositive regions. When electrons are lost at the anode, oxidation reactions occur, causing the anode to degrade (corrode) while the cathode is untouched. The size of the corrosion current is proportional to the potential difference in the system. That is, the more significant the potential difference, the higher the corrosion current generated, and hence the more severe the anode corrosion rate.