What is a foreskin ?!
Question:
What is a foreskin ?
Answers:
It's the elastic skin that covers the head of the penis. It feels just like your eyelids (and is also moist inside). It is removed via circumcision, a practice common in the USA but becoming less so.
Illustration:
http://www.nlm.nih.gov/medlineplus/ency/...
Information:
http://www.cirp.org/pages/anat/...
Source to 'less common' claim:
http://www.cnn.com/2007/health/06/18/cir...
It slides back as you wish.