A fuel cell consists of two electrodes separated by an electrolyte. In most cases, hydrogen fuel is fed into the anode of the fuel cell. Oxygen (or air) enters the fuel cell at the cathode. Encouraged by a catalyst, the
hydrogen splits into protons and electrons. The protons pass through the electrolyte. The electrons must
take the long way around, creating a separate current that can be utilized before they return to the cathode,
to be reunited with the hydrogen and oxygen to form a molecule of water. Individual cells are “stacked” together to generate useful quantities of power.