Two conductors close to each other sandwich a non-conductive insulating medium between them, which constitutes a capacitor. When a voltage is applied between the two plates of a capacitor, the capacitor will store charge. The capacitance of a capacitor is numerically equal to the ratio of the amount of charge on one conductive plate to the voltage between the two plates. The basic unit of capacitance of a capacitor is farad (F). In circuit diagrams, the letter C is usually used to denote capacitive elements.
Capacitors play an important role in circuits such as tuning, bypassing, coupling, and filtering. It is used in the tuning circuit of the transistor radio, and also used in the coupling circuit and bypass circuit of the color TV.
With the rapid development of electronic information technology, the update speed of digital electronic products is getting faster and faster. The production and sales of consumer electronic products such as flat-panel TVs (LCD and PDP), notebook computers, digital cameras and other products continue to grow, which has driven The capacitor industry is growing.

Capacitors are components that store electricity and electrical energy (potential energy). A conductor is surrounded by another conductor, or the electric field lines emitted by one conductor all terminate in another conductor’s conduction system, which is called a capacitor