Oxidation is a chemical process involving the addition of oxygen or any other electronegative atom, or the removal of hydrogen and any other electropositive atom
Example of oxidation:
Addition of oxygen: 2 Mg + O₂ → 2 MgO
Addition of electronegative atom: 2 Na + Cl₂ → 2 NaCl
Reduction is a chemical process involving the addition of hydrogen or any electropositive atom, or the removal of oxygen or any electronegative atom