A follicle is one of the tiny pockets in the skin that a hair grows from. Each hair sits in its own follicle, like a plant in a little bag. People say clogged follicles when those pockets are blocked, which can lead to spots. Though actually, it is less a hole and more a small sac — the Latin folliculus meant a little bag, from follis, a bag or bellows. Doctors also use follicle for other small bag-like parts of the body (you may meet ovarian follicle later in biology), but the sense you will hear first is the hair follicle. A hair-care and biology word, not everyday chat unless someone is talking about skin.