Introverts are people who enjoy spending time alone or find that they are able to unwind and "recharge" more effectively when they are alone. Extroverts, on the other hand, love the hustle and bustle of the outside world and feel recharged when they spend time with others. According to some estimates, extroverts outnumber introverts, and since they make for a bigger piece of the pie, society is more accommodating to their needs. 
Extroverts are considered the life of the party and more often than not, people think of them as interesting individuals with strong personalities, regardless if they are or not.

A large part of society views people who are reserved and don't talk much to be boring, antisocial and even miserable.

The truth is much simpler than that. 

Introverts are just not as interested in spending energy on pointless chit-chat. Where others are content with surface-level communication, introverts dig deep and go straight to the point without wasting time and energy with pointless fluff and unnecessary sensationalism.

And since they don't care for small talk, they can remain silent for a while in a group, giving the impression that they are snobs. 

If you force them to take part in a conversation they're not particularly interested in, they may become restless and disengaged, hoping to find a way out. 

But if you engage them in a topic they care about, you could see a completely different demeanor. Their words will be filled to the brim with passion and you may wonder if they're the same person. 

Introverts may not be loud or outgoing, but their ideas are full of life, and their thoughts are deeper than they seem. Don't let their quietness fool you. They have a lot to offer.

If you give them the chance to express themselves freely by showing them that you are interested in hearing their thoughts, you will probably end up considering them one of the most interesting and multilayered people you have ever met.

They aren't all as antisocial as people think they are. It's just that every social activity, especially if it involves many people, drains their batteries, and they need time to recharge. 
They can have a good time surrounded by people, but they can have just as a great time being by themselves. These conflicting needs can cause a lot of inner turbulence. They may want to go out and have fun, but if they go through with it, they might end up regretting it and thinking it would be better if they stayed home. 

Introverts are just as complex as extroverts, but they must be treated with respect and empathy. Avoid making assumptions about them based on stereotypes and take time to understand them as individuals.

At the end of the day, introverts and extroverts are beautiful in their own different and unique way, and we should never forget that, no matter who we're interacting with.