These words denote pigmented or reddish marks or nodules on the skin that may be permanent and either are present at birth or develop later on in life. Mole refers to a type of permanent spot which may vary in colour from yellowish brown to dark brown. Moles are usually congenital in origin and may be large or small, flat or protuberant, some having sprouting hairs. Occasionally they become malignant. They are often removed, either for cosmetic reasons or as a precautionary measure, if they grow larger or undergo any change in appearance. At various times in history a mole on the face of a woman, especially on the cheekbone, has been highly prized and referred to as "a beauty mark" or "beauty spot" because it serves to set off the whiteness of the skin.

A birthmark is often a mole , but birthmark may also take other forms, most commonly that of elevated pink or bright red growths (called in medicine haemangiomas), sometimes covering large areas of the skin. Popularly called "strawberry marks" or "port wine stains," such birthmarks are composed of clusters of small, surface blood vessels and capillaries. Naevus is the technical term for both mole and birthmark .

Freckle applies to one of a large colony of small, flat, brown or tan spots on the skin, which are not congenital. They tend to appear on the fair, rosy complexion of people with sandy or red hair and multiply when the skin is exposed to the sun, and often fade or disappear entirely during the cooler seasons. Unlike moles or birthmarks , freckles are rarely considered blemishes, as they are very common and often considered attractive.