The term "dark skin" refers to a person's complexion or color, which is determined by the amount and type of melanin pigment present in their skin. Melanin provides protection against ultraviolet radiation from the sun, and people with darker skin tones typically have more melanin than those with lighter skin tones. Dark skin can be a result of genetics or exposure to the sun over time. The phrase "dark skin" is often used as a descriptor for individuals who fall within the range of brown, black and other darker shades on the Fitzpatrick scale which measures human skin color.