A hair follicle is a formation of epidermal origin, anchored in the dermis and consisting of a hair and its sheath.
The formation of hair follicles occurs early. They begin to appear as early as the second month of gestation. These follicles will continue to form for the entire duration of the pregnancy. At birth, the baby will indeed have the entire supply of follicles with which it was genetically equipped and from this moment on, no others will form.

The scalp is an ultra-specialized area of the skin, where hair is anchored. Like other hair, also the hair on the scalp originates from a hair follicle, called a bulb.