Energy can be stored as potential energy by stretching a bow string, stretching a spring, compressing a gas, or lifting a book. It is also possible to store energy as potential energy in an electric field, a capacitor is a device capable of storing this potential energy from an electric field.
Basically the capacitors are made up of two conducting electrodes that we will call plates, separated by a minimum distance with an electrical insulator, called a dielectric. Connected to these plates are the electrical terminals of the capacitor.
If we connect the terminals of a capacitor to a source, one of the plates will receive a certain amount of electric charges, electrons, while the other plate will yield an equal amount of charges, thus generating a difference of electric potential between the terminals of the capacitor, says The capacitor is then charged. Note that it is not possible to form a closed circuit because of the dielectric.
We then have a certain amount of energy that has been stored in the electric field of the capacitor, this energy is returned to the circuit when the voltage of the source tends to decay, it is said then that the capacitor is discharging.
The property that the capacitor has to store these loads and then return them to the circuits to which it belongs is called capacitance and its unit of measurement is Farady represented by the letter "F". The Farady unit of measurement is very significant and so it is like its representation in submultiples, for example in micro-farady.
