Nuclear energy is the stored potential energy in the nucleus of an atom. This form of energy is released either when unstable nucleus splits into smaller nuclei , known as fission, or when nuclei fuse together, a process known as fusion. Compared to this, light energy is a form of electromagnetic radiation such that it is composed of photons, which are small packets of light energy. Each photon has a characteristic wavelength, frequency, etc. Light energy has photons which have no mass whereas nuclear energy comes from nucleus, and involves mass.
