What is a corn (on the foot)?
A “corn” is a small circular thickened lesion in the skin of the foot. It usually forms due to repeated pressure on the skin, such as the rubbing of a shoe. The name “corn” comes from its resemblance to a kernel of corn.
A corn is different from a callus in that it has a central core of hard material. People with foot deformities, such as hammertoes, often suffer from corns because the tops of the bent toes rub against the tops of shoes.