What is the essence of the catalase test?

Catalase test demonstrate the presence of an enzyme called catalase, that catalyses the release of oxygen from hydrogen peroxide. It is used to tell the difference between the non-catalase producing bacteria from those bacteria that produces an enzyme catalase. Catalase is produced by the bacteria that respire using oxygen. If an organism produces catalase, bubbles of oxygen are produced when hydrogen peroxide is added to it.