In other words, let's look at the following decomposition reaction. This decomposition reaction is also an oxidation reduction reaction because our O gets oxidized while our H gets reduced. In other words, in this molecule, our O has an oxidation state of negative two. And here our O has an oxidation state of zero. So if it goes from negative two to zero, it's oxidized, while this guy goes from positive one to zero. So it's reduced, it gains electrons.