Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Corns and Calluses ?
    ### Response:
    Corns and calluses are caused by pressure or friction on your skin. They often appear on feet where the bony parts of your feet rub against your shoes. Corns usually appear on the tops or sides of toes while calluses form on the soles of feet. Calluses also can appear on hands or other areas that are rubbed or pressed.
    