Suntan Capacitors and battery's different
A capacitor is a bit like a battery, but it has a different job to do. A battery uses chemicals to store electrical energy and release it very slowly through a circuit—sometimes (in the case of a quartz watch) it can take several years. A capacitor generally releases its energy much more rapidly—often in seconds or less. If you're taking a flash photograph, for example, you need your camera to produce a huge burst of light in a fraction of a second. A capacitor attached to the flash gun charges up for a few seconds using energy from your camera's batteries. (It takes time to charge a capacitor and that's why you typically have to wait a little while to take a flash photo.) Once the capacitor is fully charged, it can release all that energy in an instant through the xenon flash bulb. Zap!
Capacitors come in all shapes and sizes, but they usually have the same basic components. There are the two conductors (known as plates, largely for historic reasons) and there's the insulator in between them (called the dielectric). The two plates inside a capacitor are wired to two electrical connections on the outside called terminals, which are like thin metal legs you can hook into an electric circuit.
