Explain the following: (a) Oxidation (b) Reduction

(a) Oxidation: When a substance gains oxygen or loses hydrogen during a reaction, it is called that the substance is oxidized. This phenomenon is called oxidation.
In the following reaction:
copper gets oxygen and hence is oxidized.
$$ 2Cu + O_{2} +Heat \rightarrow 2CuO $$

(b) Reduction: If a substance loses oxygen or gains hydrogen during a reaction, it is that the substance is reduced. This phenomenon is called reduction.
In the following reaction:
zinc loses oxygen, and hence called is reduced.
$$ ZnO + C \rightarrow ZnO $$