To better understand the differences between the two components, it will benefit you to first learn a bit more about each component individually. Things like their purpose, working principle, construction, etc. However, if you already have a knowledge of both components, you can skip straight to the capacitor vs inductor section. Capacitors are one of the three fundamental passive components used in electrical and electronic circuits (the other two being resistors and inductors). A capacitor is a two terminal passive component which has the. A capacitor is constructed using two metal plates which are separated by an insulating material known as the dielectricas seen in the. When a capacitor is connected to a power source (like a battery), it stores the received energy in the form of the electric field which we have just discussed. The amount of energy stored. The simplest form of a capacitor is two metal plates separated by a dielectricas we saw earlier. When a voltage is applied to a capacitor, an electron is added to one plate making it negatively.