Aluminium electrolytic capacitors are polarized electrolytic capacitors whose anode electrode (+) is made of a pure aluminum foil with an etched surface. The aluminum forms a very thin insulating layer of aluminium oxide that acts as the dielectric (or insulator) of the capacitor. They come in a variety of styles, sizes, and series.

A ceramic capacitor is a fixed-value capacitor where the ceramic material acts as the dielectric (electrical insulator). It is constructed of two or more alternating layers of ceramic and a metal layer acting as the electrodes. The composition of the ceramic material defines the electrical behavior, and therefore, applications.

Film capacitors, plastic film capacitors, film dielectric capacitors, or polymer film capacitors (generically called "film caps"), as well as power film capacitors, are electrical capacitors with an insulating plastic film as the dielectric (insulator), sometimes combined with paper as carrier of the electrodes.

Some film capacitors of special shapes and styles are used as capacitors for special applications, such as RFI/EMI suppression capacitors for connection to the supply mains, also known as safety capacitors. Safety capacitors protect people and devices from high voltage surges by shunting the surge energy to ground.

A tantalum electrolytic capacitor is an electrolytic capacitor, which is a passive component of electronic circuits.  It consists of a pellet of porous tantalum metal as an anode, covered by an insulating oxide layer that forms the dielectric, surrounded by liquid or solid electrolyte as a cathode.