Dry skin develops when your skin loses water too quickly and becomes dehydrated. Age, medical history, the season and bathing habits may lead to dry skin.
Oily skin is the result of the oil (sebaceous) glands in the skin producing large amounts of oil. Oily skin means excess oil on the face produces a persistently shiny or greasy appearance.
Oily to normal skin, or combination skin, usually means that you have an oily forehead, nose and chin – the so-called T zone, with normal or dry skin on the cheeks
Sensitive skin is a skin condition in which skin is prone to itching and irritation experienced as a subjective sensation when using cosmetics.
Normal skin is simply a definition for an outer dermis that is balanced to the correct ratio between oily and dehydrated.