The common term for the process of respiration in animals is simply respiration. This biochemical process involves breaking down glucose and oxygen to produce energy, primarily in the form of ATP (adenosine triphosphate). Respiration occurs in two main stages: anaerobic and aerobic respiration. In aerobic respiration, oxygen is used, while anaerobic processes do not require oxygen. This process is critical for sustaining life, as it provides the energy needed for various bodily functions.