Capacitors are the electrostatic complement to electromagnetic inductors. Both capacitors and inductors store electrical energy, usually for only short periods of time because there are electrical losses associated with both devices. Capacitors store energy in the electrical field between two charged conductors; inductors store energy in the magnetic field surrounding a current-carrying conductor. Google is definitely your friend here! A good place to start is
an introductory course in Physics with some calculus.
Or, if math and theory isn't exactly your thing right now, grab a goodly variety of capacitors from your local electronics emporium, a few resistors, a few LEDs, some dry-cell batteries and battery holders, a cheap multimeter and perhaps a solderless breadboard and begin experimenting. Some capacitors (electrolytics) are polarized, so you need to pay attention to that. Batteries and LEDs are polarized, too, and must be connected properly. Be prepared to "let the magic smoke out" of a few components until you get a "feel" for what your are doing. Be sure to memorize
all the relations in that chart you are using as your avatar. Have fun! Learn by doing!
BTW, if you charge a largeish non-polarized capacitor (several microfarads) by temporarily connecting it across a battery, it will retain most of that charge for awhile when you disconnect the battery. If you then connect the capacitor across a largeish inductor (the primary of a power transformer weighing a few pounds will do), an amazing thing happens: the capacitor discharges into the inductance of the primary winding, which begins to build up a magnetic field, all the while the electrostatic field in the capacitor is diminishing. Then, as soon as the magnetic field in the inductor stops increasing, it begins to decrease and generates a voltage that charges the capacitor up in the opposite direction! When the magnetic field in the inductor ceases to decrease, the charge transferred back to the capacitor starts the cycle all over again, but now with the charge on the capacitor reversed. Electrical energy keeps sloshing back and forth between the capacitor and the inductor, slowly dissipating the energy in each cycle as heat in the resistance of the connecting wires and the resistance of the inductor winding. A clever person could design a circuit that would replenish the energy lost during each cycle, sort of like pushing on a playground swing at the right moment to sustain its motion. Voila! That clever person has constructed an
LC oscillator! The period of oscillation will depend on the square root of the product of the value of capacitance and the value of inductance used. Larger capacitance and/or larger inductance means longer period of oscillation.
Making oscillators is just one thing you can do with capacitors. And, sometimes, you don't even need inductors to do that...