Insole
The insole is an insert in the shoe, sometimes, it is a part of the shoe, and other times it is glued or removable. Its function is to increase comfort, flatten minor irregularities from the shoe construction, insulate the shoe, and wick sweat away from the foot. Anatomically shaped insoles also have a corrective function, although, in barefoot shoes, you won’t find insoles with arch support or a raised heel.