Hydroquinone works as bleaching agent for skin and works as skin-lightening agent.
Skin bleaching agent
Hydroquinone works by blocking the process in the skin that leads to discoloration. Hydroquinone helps to lighten the dark patches of skin caused by pregnancy, injury to the skin.
Benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene.