How florescence works?

According to Bohr, electrons revolve around the nucleus in definite circular paths. These paths are called the orbits. Bohr further explains that when an electron jumps from one orbit to another, it emits or absorbs energy depending upon whether it moves from a higher orbit to lower one or vice versa. 

But if an electron jumps from one orbit to another orbit and if there are only orbits with no intermittent subways then one should only see an instant flash of light coming out of the body that undergoes electron shift. Actually, that is not the case always. The reason is the presence of smaller pathways within an orbit. The electron when tries to jump from the higher orbit to lower orbit, instead of a full leap, it moves through several energy states within the same orbit, prior to jumping to the lower orbit. The following diagram will make the idea more clear.

As the energy released in this case is lower than that would have been released in case of simple jumping of the electron so this phenomenon has been given a new name "Fluorescence". It is a phenomenon usually to see in the glow sticks used commonly in parties nowadays.