What is the ozone? is it possible to restore the depletion that has occurred over time? if so how?

Ozone, or trioxygen, is an inorganic molecule with the chemical formula O ₃. It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O ₂, breaking down in the lower atmosphere to O ₂. Earth's ozone layer has been damaged by well-intentioned chemicals-chlorofluorocarbons, used for refrigerants and aerosol spray-cans-that have the unintended consequence of destroying ozone molecules.