Why does aqeous fluorescein shine when exposed to UV light?

I know that (aq) fluorescein *"absorbs"* UV light and releases light in the visible spectrum , but how does it do that. It is a really interesting and useful organic chemical and I just wanted to know what goes on in it so that it lights up.


![Fluorescein dissolved in water](https://img00.deviantart.net/b0ac/i/2013/154/8/1/yay_fluorescein_by_hassium108-d67qtip.jpg)




The process is called [fluorescence](https://en.wikipedia.org/wiki/Fluorescence). Some substances, such as calcium sulfide, $\ce{CaS}$, absorb light and release it slowly in a process called [phosphorescence](https://en.wikipedia.org/wiki/Phosphorescence), glowing for some time after the source of light is removed.


 3