Anaerobic respiration is a type of cellular respiration that occurs in the absence of oxygen. There are several synonyms for anaerobic respiration, including fermentation, anaerobic metabolism, and anaerobiosis. Fermentation is a process that breaks down sugars into simpler compounds to produce energy. Anaerobic metabolism refers to the metabolic process that occurs in the absence of oxygen, which produces energy through fermentation or other chemical reactions. Anaerobiosis describes a physiological state in which cells are able to survive in the absence of oxygen by using alternate energy sources. Although these terms are related to anaerobic respiration, they each have their own unique characteristics and processes.