Aerobic respiration is the process of producing energy in the presence of oxygen. It occurs in the mitochondria of cells and involves the breakdown of glucose to produce ATP (adenosine triphosphate), which is the energy currency of cells. During aerobic respiration, glucose is first converted to pyruvate through a process called glycolysis. The pyruvate then enters the mitochondria where it is further broken down in a process called the Krebs cycle, ultimately producing ATP.

On the other hand, anaerobic respiration is the process of producing energy without oxygen. It occurs in the cytoplasm of cells and is less efficient than aerobic respiration. During anaerobic respiration, glucose is converted into pyruvate through glycolysis, but instead of entering the mitochondria, the pyruvate is converted into lactic acid or ethanol, depending on the organism. This process also produces ATP, but only a small amount compared to aerobic respiration.

In summary, the main difference between aerobic and anaerobic respiration is that aerobic respiration requires oxygen and is more efficient, while anaerobic respiration does not require oxygen and is less efficient.