In the lab we concentrated on electrolysis involving inert electrodes. Usually that means either graphite, platinum or stainless steel. But if other metals are used it is possible that they themselves might be oxidized instead of water or ions present in the solution. This is the basis for electroplating in aqueous solution. The anode electrode dissolves (is oxidized) to replace ions in the solution which have plated onto the cathode. Even if plating is not the object of a particular electrolysis, the anode may still dissolve if its oxidation potential is smaller than that of water. You will see that happen in the last experiment of the course.