Aerobic means with oxygen, and anaerobic means without oxygen. An aerobic exercise stimulates the heart rate and causes breathing to become faster but not so much that the activity cannot be sustained. An anaerobic exercise causes breath to be lost quickly.
Regular aerobic exercises improve health, fitness and much more. They may help reduce the risk of cancer, osteoporosis, depression, diabetes and cardiovascular disease along with reducing the risk of obesity. Aerobic exercises can also be considered anaerobic if they are performed at a high enough intensity. In turn, anaerobic exercises can also be considered aerobic if they are performed at a low enough intensity.