Insoles, also referred to as inserts or inlays, are the interior liner placed in a shoe that is in contact with the plantar surface of the foot. Many shoes are manufactured with a removable insole that can be replaced with an insole designed for a specific purpose such as odor control, moisture control, arch support, cushioning, reducing foot pain, or foot realignment. Depending on the required purpose, insoles can be classified as prefabricated, customized, or custom-made.