>> Capacitors are devices that provide electrical energy storage of two types.
One, where there's two conducting surfaces with an insulator between so that one side,
when you apply a voltage to it,
it can't get through the insulator,
so it piles up as charge at every little atom on both sides,
one plus and one minus, and stores energy.
Polypropylene, when it's built in a manner where it's stretched in two sides,
it comes out as a film, and then you stretch it both lengthwise and
sideways to orient all the molecules in the direction of the surface of the film.
Roll up the film and send it into the winding machines, so it wind
it into with the aluminum foil we are making to make the capacitors.
The other one was stored energy with the similar thing except that
the insulator level is the metal oxide.
The insulating film is deposited by anodizing aluminum,
and you get very high capacitor levels with electrolytic capacitors.
So, both tantalum oxide and aluminum oxide are
very good preventers from electrons escaping their surfaces.
That's what a capacitor is.
It's a storage of electric charge.