Sex includes a lot of things, including manual sex (when partners stimulate each other's genitals using their hands), oral sex (when partners stimulate each other's genitals using their mouths and tongues), vaginal sex (commonly called intercourse, when a man inserts his penis into a woman's vagina), and anal sex (when something is inserted into someone's anus).
How about I link you to some of our basic articles, and then you can come back with questions?
Copyright 1998, 2014 Heather Corinna/Scarleteen
Scarleteen.com: Providing comprehensive sex education online to teens and young adults worldwide since 1998
Information on this site is provided for educational purposes. It is not meant to and cannot substitute for advice or care provided by an in-person medical professional. The information contained herein is not meant to be used to diagnose or treat a health problem or disease, or for prescribing any medication. You should always consult your own healthcare provider if you have a health problem or medical condition.