Final answer:
Oxidation involves the loss of electrons, which can be associated with gaining oxygen or losing hydrogen, and is part of redox reactions along with reduction.
Step-by-step explanation:
Oxidation is a chemical reaction that results in the loss of electrons. This concept is key to understanding redox reactions, which involve both reduction and oxidation processes happening simultaneously. When a substance undergoes oxidation, it may also experience a gain of oxygen or the loss of hydrogen.
These changes are often accompanied by an increase in the oxidation number of the element involved. Conversely, reduction is characterized by the gain of electrons, loss of oxygen, or gain of hydrogen, typically resulting in a decrease in the oxidation number.