The foreskin is the protective layer of skin that covers the glans (head) of the penis. This skin is very elastic because as you go through puberty, it slowly becomes less attached to the penis, allowing you to retract it and expose the head. You should never force the retraction of the foreskin, but once you’ve entered puberty you should retract it as far as it will comfortably go each time you bathe in order to clean underneath it.