write different between nuclear fission and nuclear fusion

Nuclear fission	Nuclear  fusion
In fission reactions, a heavy nucleus is split into two nuclei with smaller mass numbers.	In fusion reactions, two light nuclei are combined to form a heavier, more stable nucleus.
High-speed neutrons are required in nuclear fission reactions.	Very high temperature is required for nuclear fusion reactions
The amount of energy required to split two atoms in a fission reaction is less as compared to fusion reaction.	A tremendous large amount of energy is required to bring two or more protons close enough to overcome their electrostatic force of repulsion.
Tremendous large amount of energy is released by fission reactions; but lower than the energy released by nuclear fusion.	The energy released by fusion reactions is three to four times greater than the energy released by fission reaction.
The energy produced by nuclear fission reactions is used in nuclear power plans for generation of electricity.	The energy produced by fusion reaction is not controlled as far and cannot be used for generation of electricity. It is used in Sun through which energy is created.