Calluses refer to a firm, rough patch of skin that develop from overuse or irritation, most particularly found on the feet which can be softened with soaking and pumice.
Calluses a re areas of skin that thicken in response to repeated pressure and friction from repeated rubbing. They are the body's way of protecting the skin and the structures beneath it from injury. Calluses can form on the skin of any part of the body that is exposed to excessive pressure or friction. It is common for calluses to form over a bony spot, such as the toes, fingers or elbows. Painful calluses typically occur on the sole of the foot, on the heel or under the five metatarsal heads (i.e., the area where the long inner bones of the toes extend into the foot). These areas typically bear most of the pressure and friction from standing and walking. As the callus thickens, it causes more pressure against the skin inside the shoe, causing pain.
Visit Dr. Scholl's website for products against calluses - http://www.drscholls.com. (See Dr. Scholl)
Author's Note: Dr. Scholl and Body Shop have plenty of products to soften foot calluses and also pumice stones. Dr. Scholl have also products to avoid building up of calluses like callus cushions and callus removers.