The main differences between aerobic and anaerobic respiration is the requirement of oxygen. Aerobic respiration occurs in the presence of oxygen whereas anaerobic respiration occurs without oxygen.
The main differences between photosynthesis and cellular respiration is that photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, while cellular respiration is the process by which living organisms break down glucose to release energy in the form of ATP.