Arch Support generally refers to the part of the insole of the shoe that raises right at the level of the arch to provide support to the midfoot. Arch Support also refers to individual insole cups with a molded shape that fit the arch and are placed inside the shoe to help relieve foot or heel pain.
About Sandals:
Sandals are footwear made of a sole that is held to the foot utilizing straps or thongs. Sandals are characterized by exposing the foot.