The difference between cellular respiration and fermentation is that, cellular respiration needs oxygen while fermentation does not. The other difference is water molecules are produced during cellular respiration but during fermentation it does not. Only glycolysis happens in the cytoplasm during cellular respiration while all fermentation reactions happen in the cell's cytoplasm. Finally, cellular respiration induces a net gain of 32 ATPs (adenosine triphosphate) while fermentation induces a net gain of 2 ATPs (adenosine triphosphate).