Corn and calluses have obvious differences, as these two conditions arise from different mechanisms. Corns are what we commonly refer to as ordinary warts, which are caused by viral infections. Such viral infections are typically related directly to a decline in one's immune system, leading to the disease. The usual presentation is a change on the surface of the skin, generally appearing as tumor-like. On the other hand, calluses do not protrude on the surface and are mostly caused by local pressure and other similar factors. This condition has little to do with viral infections. Nevertheless, the treatment methods for these two conditions are quite similar. For example, they can be removed through laser surgery or treated using certain ointments to achieve healing effects. (The use of medications should be guided by a doctor.)