The sun and stars glow by incandescence. If you lift a rock, your muscles are supplying energy to raise the rock to a higher-energy position. If you then drop the rock, the energy you supplied is released, some of it in the form of sound, as it drops back to its original low-energy position. It is somewhat the same with luminescence, with electrical attraction replacing gravity, the atomic nucleus replacing the earth, an electron replacing the rock, and light replacing the sound. There are several varieties of luminescence, each named according to what the source of energy is, or what the trigger for the luminescence is.
Bleaches enhance their whitening power with a white fluorescent material.
Photoluminescence should not be confused with reflection, refraction, or scattering of light, which cause most of the colors you see in daylight or bright artificial lighting. Photoluminescence is distinguished in that the light is absorbed for a significant time, and generally produces light of a frequency that is lower than, but otherwise independent of, the frequency of the absorbed light. Chemiluminescence is luminescence where the energy is supplied by chemical reactions. Fireflies glow by bioluminescence. Electroluminescence is luminescence caused by electric current.