Final answer:
Oxidation refers to the loss of electrons, gain of oxygen, or loss of hydrogen, while reduction refers to the gain of electrons, loss of oxygen, or gain of hydrogen. These processes occur together in redox reactions.
Step-by-step explanation:
Oxidation is the loss of electrons, the gain of O, or the loss of H. Reduction is the gain of electrons, the loss of O, or the gain of H. These reactions are coupled and called redox reactions. Electrons' loss or gain is easily recognized in inorganic chemical reactions.