Anodic and Cathodic:

What is usually meant by the terms anodic and cathodic and when is an electrode an anode or a cathode?

Answer:

An anodic reaction is an oxidation. A cathodic reaction is a reduction. An anode is an electrode at which an oxidation reaction is taking place. Its potential need not have a positive value but oxidation occurs more easily the more positive the potential. Therefore, the anodic direction is to more positive potentials. Similarly a cathodic or reduction process could occur at a positive potential but as the electrode becomes more negative it becomes more cathodic.