There is a good book called “Raising a Spirited Child” that explains introverts and extroverts really well.
The difference between them is where they get their energy from. Meaning, after a long day at school an introvert needs to be by themselves so they could have energy to be able to be by themselves and therefore will go to their room to recharge, it doesn’t mean that they’re “in a shell”; while extroverts get their energy from people so after a long day at school they will tell you everything that happened.
Also extroverts think through problems aloud while introverts think through a problem quietly.
It’s not bad or good, their just DIFFERENT