Originally Posted by Silmarillion
An extrovert recharges his "batteries" by being with other people. An introvert recharges his "batteries" by spending time alone.
Introverts can love spending time with people, and extroverts can love spending time alone. Introverts can be outgoing, and extroverts can be shy. It's all about energy.
Um no it's not 'All about energy' it's about behavior, social interaction and internal approach to interacting to others in social settings.