When we walk, our weight is carried on our heels and then transferred to the ball of the foot. The skin is thicker in these places to withstand the pressure. When the pressure becomes excessive corns and callus can form as a protective response.
 
A corn is a localised area of thickened skin. It can occur on areas of pressure for example, the soles of your feet and on the tops or the toes, they may also occur in between the toes and also down the side of your toenails; anywhere that the skin comes under pressure or friction.

Most corns, like calluses are a symptom of an underlying problem, for example, a bony deformity, a particular style of walking or inappropriate footwear. They can be extremely tender and cause considerable pain and can even become infected. 
  

What to do

You can control the build up of hard skin by rubbing the area with a pumice stone or footfile. Also the use of a daily moisturising cream can also help to control the situation. If this does not seem to do the trick then contact your local state registered podiatrist. Never try to get rid of the corn yourself by using a blade or any sharp instrument, you way end up making matters worse. Corn cures or plasters contain strong acid and can be dangerous, their use is not advised.
If the corn is painful, then a visit to your local state registered podiatrist. They will be able to advice you on how this has come about and, where possible, how to prevent it happening again. They can get rid of the corn and construct a device to redistribute the pressure so as to help prevent it from recurring.