Circumcision (the surgical removal of the foreskin at the tip of the penis, usually done shortly after birth) is a cultural tradition for many individuals. Those who are uncircumcised may look just like everyone else in some countries, and be the only one with a cover over the glans (the skin at the rim of the penis where tons of nerve ending live) in locker rooms elsewhere.
Circumcision is not a medical necessity, and some say that because the foreskin has a lot of nerve endings, it makes sex more pleasurable to keep the foreskin on. Others swear that circumcision enhances feelings by leaving the glans more exposed. There are some data that uncircumcised penises have a higher risk of acquiring certain STIs, such as chancroid (shows up as an ulcer on the penis) and HIV. If you’re not circumcised, you need to keep your penis clean, because warm, moist areas can trap bacteria. When showering, pull back the foreskin and wash that area with soap and water.