How does oxidation work?
Oxidation occurs when one atom takes electron density from another atom.
Some atoms have a greater electron negativity so have a greater attraction for electrons. Oxygen is an example of an element that has a high electron negativity and draws electron density away from other elements.
When another element has its election density draw away from the element the elements is said to have been oxidized. The process of electron density transfer is named oxidation after Oxygen which tends to take electron density from almost every other element.