The difference between aerobic and anaerobic capacities lies in how the body generates energy. Aerobic exercise relies on oxygen to fuel activity and is typically performed at a moderate intensity over extended periods. In contrast, anaerobic exercise involves short bursts of intense effort where the body relies on stored energy without the need for oxygen, such as sprinting or weightlifting. Both capacities are crucial for comprehensive fitness, but they target different energy systems and contribute to various physical adaptations.