What makes you who you are? Is it your background? Your culture? Your race? Your likes and dislikes?
All of these contribute to a certain degree, but none more than your overall personality type. Introverts and extroverts are at opposite ends of the personality spectrum. Of course, you can place yourself anywhere along the spectrum, but you’re either one or the other.
This book explains how introverts and extroverts think, behave, and react differently to various situations. The most important thing is: one is not superior to the other, however, society would have you believe otherwise.