A cream is a preparation of a medication for topical use (on the skin) that contains a water base. Essentially, it is a preparation of oil (often lanolin or petrolatum) in water. An ointment is a preparation of a medication for topical use that contains an oil base – essentially a preparation of water in oil.
Creams and ointments contain a different proportion of oil to water. Ointments have a higher concentration of oil, compared to creams. The more oil, the greasier and stickier the product. Creams may work better on larger areas of the skin because of their “spreadability” factor, compared to ointments.