A capacitor is a passive element which can store a charge when a voltage is applied across it. The charge storing capacity can be determined by product of the capacitance of the capacitor and voltage applied across it. The value of the voltage and capacitance are mentioned on the label of the capacitor. The electrolytic capacitor has polarity, polarity means it has designated positive and negative legs. The leg which is longer is positive pin and shorter leg is negative. Negative pin has negative symbol marked on it. They are most widely used capacitor type out there and can be used in wide range of applications like filter circuits, ripple smoothing, Resonant circuits, Isolation and noise removal circuits. Care should be taken as swapping the legs or applying more voltage across its legs might result in overheating and even bursting of the capacitor.