What is called redox reaction (or oxidation - reduction reactions)? Explain it with suitable examples.

Explanation

A reaction in which one reactant gets oxidised and the other reactant gets reduced, then such reaction is called redox reaction (or oxidation – reduction reactions).
OR
A reaction in which both oxidation and reduction reactions occur simultaneously is called redox reaction (or oxidation - reduction reactions).
Examples of redox reaction :

In above reactions, CuO, ZnO and `MnO_(2)` are reduced to Cu, Zn and `MnCl_(2)` respectively while `H_(2)`, C and HCI are oxidised to `H_(2)O, CO` and `Cl_(2)` respectively.
Similarly, rusting of iron (corrosion) is also a redox reaction.