RC (resistor capacitor) network capacitors are types of capacitors (devices which store electrical charge in a circuit) where the insulator is made from metallised paper (a special paper with a metallic layer, usually aluminium).
RC network capacitors are made up of two metallic plates with a dielectric material (insulator) in between. When you apply a voltage over the two plates, an electric field is created. Positive charge will collect on one plate and negative charge on the other. The capacitor stores this charge and then releases it.
RC networks are used in electronics and in particular electronic circuits and are suitable for use in DC (direct current) and AC (alternating current) applications. RC network capacitors have a number of essential applications in circuit design, providing flexible filter options, noise reduction, power storage and sensing capabilities.