1.With aerobic exercise oxygen is carried through your breath to the muscles giving them the energy needed to sustain the effort. Aerobic is best defined as, not using too much of your strength to do some exercises.
2. Aerobic means "with oxygen" and anaerobic means "without oxygen"
3. Anaerobic is when you are out of breath just in a few moments like when you are lifting weights, sprint, climb a long flight of stairs. Its basically defined when you are using a lot of your body strength to do some exercise which can be bad for your muscles and bones.
Hope this helped :)