What Is the Difference Between "ferric" and "ferrous"?

The difference between ferric and ferrous iron is that ferric iron is in a plus-3 oxidation state, while ferrous iron is in a plus-2 oxidation state. This means that ferric iron needs to share three electrons with an oxygen molecule to make the ion neutral, while ferrous iron only needs two more electrons. With the addition of oxygen, the ferrous ion can easily become a ferric ion.