There are two kinds of people in the world: Introverts and extroverts, and each of them are poles apart from each other with their beliefs, activities, ways to have fun etc.
Introverts are usually shy but contrary to popular beliefs, they don't hate going out and partying. They just utterly despise it. Out of the many things that can upset an introvert, the most dangerous one is forcing them to talk about their emotions in public. If you do so, they may kill you afterwards. Apart from that, introverts are pretty harmless.
Traits: Shy, dislikes gatherings, most of them are either gamers or avid readers.
Strength: Can live without human contact for a long time.
Weakness: Direct eye contact.
Idea of fun: Getting holed up inside his/her room reading books, watching tv shows and playing video games.
Fear: Having to talk in front of more than one person, offending someone.
If you violate any of the above guidelines, then you might experience some things in the upcoming days like receiving lukewarm water when you asked for hot water or getting only one spoon of sugar in your coffee when you asked for 3.
A pair of introverts is called an awkward. There is no term for a group of them as gathering of more than 2 introverts happens only once every decade. Introverts make friends in a weird way. An extrovert finds them and makes them their friend.
Extroverts on the other hand, are the exact opposite. They continuously need another human to have "fun". They recharge their energy but hanging out with other humans. Prolonged deficiency of human company can have a direct impact on their behaviour and they may wander around to search for a fellow Homo sapien like the way a zombie searches for brains.
Traits: Outgoing, loves sports.
Strength: Direct eye contact.
Weakness: Solitude.
Idea of having fun: Dancing with a lot of people in a dark room with ear-numbingly loud music and consuming a liquid that makes your speaking abilities go downhill, watching football.
Fear: Being alone for more than 0.1seconds.
Extroverts are almost always found in a group although a pair may be seen in the wild but that is very rare. Popular sites to find one are bars, stadiums and the gym.
P.S.- This is just for humour and you're not supposed to take this literally.
Images are under CC0 lisence.