Arch supports are orthopedic devices used to provide support and cushioning for the feet. They are typically made of plastic or rubber and are designed to fit into the shoe. The term arch supports can refer to several different components, including soles, jambs, insoles, innersoles, and piers. Soles are the bottom part of the shoe that comes in contact with the ground. Jambs are the sides of the shoe that connect the sole to the upper. Insoles are the removable inner layer of the shoe that provides cushioning and support. Innersoles are the innermost layer of the shoe that provides additional cushioning and support. Piers are the vertical supports that provide stability and arch support.