I don't understand the difference between aerobic and anaerobic respiration

Aerobic respiration is respiration that uses oxygen and glucose, whilst anaerobic respiration is respiration that only uses glucose. As you can see in the equations for both types of respiration:

Aerobic respiration: glucose + oxygen à water + carbon dioxide (+ energy)

Anaerobic respiration: glucose à lactic acid (+ a little energy)

For both equations I put energy in brackets because they aren’t actually meant to be in the equation but I put them in there just as a little reminder that they are made to.

There are three more differences between aerobic and anaerobic respiration. One difference is that aerobic respiration is a lot more efficient than anaerobic respiration and so produces a lot more energy than anaerobic respiration does.  The other difference is that anaerobic respiration is only used when oxygen isn’t available. An example is when you’re running and you aren’t getting enough oxygen fast enough to be able to do aerobic respiration to provide the body with the energy it needs, then your body will use anaerobic respiration to get the energy it needs. The last difference is that after having done anaerobic respiration your body will be in what’s called oxygen debt because it doesn’t have enough oxygen inside it, so it will need to take in more oxygen to repay this debt.

A good way to remember this is to think of the ‘n’ in anaerobic respiration to stand for not. As in not with oxygen and not efficient.