What do you mean by green chemistry? How will it help decrease environmental pollution?

(N/A) Green chemistry is a production process that aims at using the existing knowledge and principles of chemistry for developing and implementing chemical products and processes to reduce the use and generation of substances hazardous to the environment.
The release of different harmful chemicals (particulates,gases,organic and inorganic wastes) causes environmental pollution.
In green chemistry,the reactants to be used in chemical reactions are chosen in such a way that the yield of the end products is up to $100 \%$.
This prevents or limits chemical pollutants from being introduced into the environment.
Through the efforts of green chemists,$H_2O_2$ has replaced tetrachloroethene and chlorine gas in the drying and bleaching of paper.