Electric conductor , usually metal, used as one of two terminals to conduct electric current through a conducting medium.
A simple voltaic cell, or battery , consists of two electrodes, usually one zinc and one copper, immersed in an electrolytic solution (see electrolyte ). When a chemical reaction occurs in the solution, cathode , which becomes negatively charged. At the same time, electrons are drawn from the copper electrode, the anode , giving it a positive charge. The difference in charge sets up a potential difference, or voltage, between the two electrodes. When they are connected by a conducting wire, electrons flow from the cathode to the anode, producing a current.