The difference between aerobic and anaerobic activities lies in how the body produces energy. Aerobic exercise, such as running or cycling, requires oxygen to fuel prolonged activities and increases heart and lung capacity. Conversely, anaerobic exercise, including weightlifting or sprinting, does not primarily rely on oxygen but instead uses stored energy sources for quick bursts of activity. Both types of exercise are essential for a balanced fitness routine, promoting cardiovascular health and muscle strength.