The names that are used to describe the different types of capacitors are the names of the dielectric materials used in its construction because the performance of a capacitor is usually dependent upon the type of material that is used for its dielectric. Also like resistors, there are also variable types of capacitors which allow us to vary their capacitance value for use in radio or “frequency tuning” type circuits.
The various types of capacitors include,
made from aluminum oxide or titanium oxide, silvered mica, metalized film made using strips of waxed or oiled paper and aluminum foil or with plastic dielectrics such as polyethylene, Mylar, polypropylene, polycarbonate, and polyester, and finally large electrolytic capacitors in the form of Aluminum Electrolytic Capacitors and Tantalum Electrolytic Capacitors either polarized or non-polarized.
Variable capacitors change value due to the variation in the overlapping area of the plates or by varying the spacing between parallel plates. Air dielectric is used for the larger capacitance values. Trimmers and smaller variable types use very thin mica or plastic sheets as the dielectric between the plates.