Like so much on the subject, it is written from the point of view of circumcision as the norm - starting with the fourth word of the title. Comments and added emphasis are in red. This is called the foreskin.
Circumcision removes the foreskin over the glans.
If a boy is not circumcised, his foreskin is left intact. This is the first time the AAP has used that word. During the first several years of life, the intact foreskin will naturally separate from the glans. This is called foreskin retraction. It enables foreskin retraction.