The difference between nuclear fusion and fission
One happens in the sun ,
one we harness energy from,
but which does what?
This happens in our power stations, and is the splitting of a nucleus that releases the energy. Usually Uranium 235 or plutonium 239. A neutron is fired at one of these elements nucleus's which makes the nuclear split into two releasing energy. This energy is then used to turn a turbine , probably by heating water, and generate electricity.
When the nucleus splits it releases 2-3 neutrons which then collide - starting the whole process of again with another nucleus in the reactor.setting of a chain reaction. The problem with using this to generate electricity is that nuclear waste is produced which has a long half life and so will not be safe for hundreds of years.
This happens in the sun when to nucleus'son collision fuse together to make a bigger one this releases energy. This happens between two very basic (Tritium and Deuterium) molecules which fuse into helium and a neutron. this does not produce harmful products and would make a much cleaner and effective energy producing method. The only problem is scientist are having trouble recreating it on earth , very high temperatures and pressures are needed and making it happen is using more energy that it is producing .
I find if you are having trouble remembering which is which remember 'fus ion' fuses.