One of the aluminum foil strips, called the anode, chemically roughened and oxidized in a process called "forming", holds a very thin oxide layer on its surface as an electrical insulator and which serves as the dielectric of the capacitor.
One of the aluminum foil strips, called the anode holds a very thin oxide layer on its surface as an electrical insulator and which serves as the dielectric of the capacitor. The anode is chemically roughened and oxidized in a process. This process is called "forming".