Humans produce two primary types of hair, vellus and terminal. Vellus hair is the soft, downy hair that lacks color. The follicles that produce vellus hair are normally shallow and the hair shaft they produce is usually small. Terminal hair, such as that of the scalp or eyebrows, is coarse, pigmented, and deeply rooted. Hair sometimes gradually shifts between types, often because of a change in the hormones of the body.