How do aerobic respiration, anaerobic respiration and fermentation differ from each other with respect to number of ATP molecules produced?

Question

While studying respiration, I came across a line in one book that anaerobic respiration is different from fermentation in the fact that the final electron acceptor in the electron transport chain in case of anaerobic respiration is any inorganic molecule other than oxygen wheres in case of fermentation it is an organic molecule. Then again it is written that since anaerobic respiration involves incomplete oxidation of glucose so the amount of energy released is way less than that released in case of aerobic respiration. 
In the following article it is mentioned that anaerobic respiration proceeds in a similar manner like aerobic respiration i.e. it involves TCA cycle and electron transport chain.

https://www.thoughtco.com/difference-between-fermentation-and-anaerobic-respiration-1224609#:~:text=Even%20though%20fermentation%20happens%20without,the%20same%20as%20anaerobic%20respiration.&text=However%2C%20instead%20of%20ending%20with,same%20path%20as%20aerobic%20respiration.

If that is indeed the case, then why does anaerobic respiration give off less energy than aerobic respiration when the only difference is in the nature of the final electron acceptor?

hcbiochem · Answer

The fundamental answer is that the energy released transferring electrons to other elements is less than the energy released transferring electrons to O2. Since not as much energy can be released here, not as many ATP molecules can be produced. The electron transport chain is structured just a little differently reducing the numbers of protons pumped per pair of electrons from NADH and so less ATP can be produced.

How do aerobic respiration, anaerobic respiration and fermentation differ from each other with respect to number of ATP molecules produced?

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