I shower daily and the next morning I have a white residue under the foreskin is that from dry skin?
It is smegma. It is normal to shed a cell layer of skin on a daily basis, this is doubled under the foreskin because two skin surfaces are in contact. Think of it as dandruff of the penis, similar to dried skin between the toes, which stays there because the penile glans is not exposed and thus does not rub off. Don't fret it's normal.
Yes. It is smegma. It is normal. It is why you should clean under your foreskin daily. Women get the same thing around the clitoris and along the labia.