Capacitors have been used since the early beginnings of electronics, and are present in almost all electronics applications, from mobile phones to power plants.

The basic construction of a film capacitor is two layers of a conductive material which is insulated with a film material.

The capacitance value is related to the surface area of the conductive layer.  The performance of a capacitor can vary substantially, depending on the dielectric insulation and the terminations between the capacitor element and the connectors.