Capacitors are one of the most common passive components in circuits just like the resistor. Capacitors store electrical charge and have different functions depending on the circuit design. The capacitance is a measure of how much charge or energy the capacitor can carry. In its most basic form, a capacitor consists of two conducting plates separated by an insulator (dielectric), which is commonly represented with its circuit design symbol. There are many different types of capacitors, made up of various dielectric material, used for many different purposes.