Capacitance
Definition
How much electric charge a device can store per volt — the measure of a capacitor's storage ability.
Symbol: · Unit: farad (F)
Technical definition
The ratio of stored charge to voltage, C = Q/V, measured in farads. A capacitor stores energy in the electric field between its plates: U = ½CV².
Example
A camera flash charges a capacitor to about 300 V, then dumps all that stored charge through the flash tube in a millisecond — far faster than the battery alone could deliver, which is why the flash is so intense.
A capacitor is not a battery. A battery stores energy chemically and delivers steady voltage for hours; a capacitor stores charge on plates and dumps it almost instantly, then needs recharging. That is why camera flashes and defibrillators use capacitors for punch and batteries for endurance — different jobs, different devices.