The head of the penis is exposed. Therefore it is easier to keep clean.
In an uncircumcised penis, the foreskin covers the head of the penis. In order to clean it, the foreskin needs to be retracted. If the foreskin is tight, that may be difficult.
...Do you have a follow-up question? Consult Dr. Mesrobian, a Pediatric Urologist with years in practice: