In electronic circuits some components require direct current power while the power supply is on alternating current. Solving this problem is one example of the usefulness of a capacitor.
This equipment is capable of storing potential electric energy for a period of time, it is built using a uniform electric field. A capacitor consists of two conductive parts called armatures and an insulating material with specific properties called dielectric.
In order to have a uniform electric field it is necessary to have a specific interaction, limiting the possible geometric shapes of a capacitor, so some examples of capacitors are: