differentiate between nuclear fission and nuclear fusion?

Nuclear fission is the process used in the production of nuclear power. Fission involves splitting the nucleus of a heavy atom, such as uranium. This yields two or more lighter nuclei and a large amount of energy.

Fusion, on the other hand, is the combination of two hydrogen nuclei into one helium nucleus, under conditions of extreme heat and pressure. Fusion is the process by which energy is created in the sun.