Calluses and corns are hard, thickened skin that builds up on parts of the foot that are exposed to friction and pressure.
Calluses are common on the soles of the feet and heels.

Corns usually form on the toes, where shoes press and rub skin against bone.

You can prevent corns and calluses by avoiding shoes that pinch or cramp your toes or by using insoles to cushion your feet. If you cannot avoid wearing shoes that rub your feet, use moleskin pads for protection.

If a callus or corn becomes painful, soak your feet in warm water and rub the callus or corn with a towel or pumice stone. You may need to do this for several days until the thickened skin is gone. 

If a corn or callus breaks open or becomes sore, see your doctor.

Do not try to cut or burn off corns or calluses. 

If you have diabetes or peripheral vascular disease, talk with your doctor about removing troublesome corns or calluses