Some more things about bypass capacitors:
-I agree that energy and not voltage is what the capacitor stores. In order to understand electronics better one must understand the physics behind this little, multicoulored "things" that we solder on a board, or we design in a schematic.
-All electronic devices have a detailed mathematical model to describe ther function. It is not the model that makes the device, but it is just a tool to understand better how it works. In the case of the capacitor we say that bypass capacitor, for instance, is used to filter the dc voltage/current from a circuit. Something was written about impendance. This is correct. How do we express it? We say that if resistor doesn't have any dependancy at all from frequence, Zr=R, that is what ever signal we apply to a resistor, form DC to UHF, the resistance will alwaysbe the same: R->Ohms
But in capacitor things are different; Because capacitor "piles" electrons to its plates, that make it respond different in terms of resistance to the movement of electrons: The bigger the amount of electrons in the plates, the bigger the resistance to the newcomers. On the other hand if electrons move to both directions because of alternating voltage across the capacitor then the resistance depends on how fast these electrons accumulate to its plates; In other words: Zc=1/(ω•C). The parameter ω=2•π•f where f is the frecuence of the alternating voltage. So for f=0, Zc is indefinite that means that there is no chance current pass through it.
I think that I gave you a rugh example on bypass capacitors. I will also post a very-very usefull article on why and how we use bypass capacitors in PCB I found a month ago. I can't do it right now, because I have at work and today is Sunday...
My apologises if I used simplicities on this explanation,
D.