Sperm are little squiggly cells that fly out of your helmet during any form of sex or masturbation due to rapid muscle contractions. Sperm can fertilise the womans egg making a fetus that is born as a "baby". Sperm are good, do not keep them too hot or they'll die.
Man - Dude i masturbated last night.
Dude - Wow man, did sperm come out?
Man - Yes, they were white.