Dark lips refer to lips with darker pigmentation than the natural color of the surrounding skin. The darkening of the lips can vary in intensity and may appear as a slight discoloration or a more noticeable and prominent darkening.
Thin lips refer to lips with less volume or fullness than the average lip size. Some people naturally have thinner lips due to genetics, while others may experience lip thinning as a natural part of aging. Thin lips can affect the overall facial appearance and maybe a cosmetic concern for some individuals.