Redox Reaction: A type of chemical reaction that involves a transfer of electrons between two species. The formation of Iron Oxide from Iron and Oxygen is an example.
Compound: A substance formed when two or more elements chemically bond together. In this case, Iron Oxide is a compound made up from Iron and Oxygen atoms.
Chemical Bonding: The joining together of atoms to form new substances. The bond between the Iron and Oxygen atoms in Iron Oxide is an example of chemical bonding.