Peer pressure is a complex social dynamic in which a peer (friend, classmate, sibling, etc.) continuously asks you to do something or manipulates you into doing something. Typically, peer pressure is bad, leading to drug use, vaping, smoking, or drinking — but it can also be used in a good way.
How do I know if I'm being peer pressured?
Peer pressure isn't always easy to spot, but once you recognize it, it becomes easier.
Say you have a friend who keeps asking you to take a hit of a vape. You refuse multiple times, until eventually you give in. This is peer pressure, and it can take many forms. This is just one example of it. Maybe a friend tells you it's cool to smoke or vape, and you finally give in.
Maybe your friend asks you to hang out, and there are other people. They're all passing a bong around until it gets to you. Your friend asks you, "You wanna try?" You say no. He asks again, and again. Maybe says something along the lines of "Come on! It'd be so cool!" or "Your loss!" That is all peer pressure — negative peer pressure.
Summary
You are being peer pressured if you are continuously asked to do something you're uncomfortable with until you give in. Peer pressure comes from friends, classmates, siblings, etc.
A note
If you were pressured into having any form of sexual intimacy with someone against your will, that is not peer pressure — that is sexual coercion (a form of sexual assault). Please report this to a trusted adult, or get help at the RAINN National Sexual Assault Hotline: +1 800-656-4673.