There is a hole in the ozone layer. What do you understand by this?

Explanation

Hole in the ozone layer:
1. The area is Antarctica region with a thin ozone layer is known as ozone hole.
2. CFCs (Chlorofluorocarbons) which are widely used as refrigerants disturb the balance between the production and degradation of ozone.
3. Ultraviolet (UV) rays and chlorofluorocarbons (CFCs) release chlorine (`Cl^(-1)`) ions, which act as catalyst in the degradation of ozone layer.
4. Chlorine ions also degrade the ozone layer.
5. The degradation of ozone layer results in the depletion of ozone causing a hole in the ozone layer.