Extroverts gain more energy from being around other people and in social situations.
Introverts (like me) can handle social situations perfectly well, but need some time to recharge afterwards. Preferably completely alone without human contact.
If I spend a day coding and just talk to my coworkers occasionally, during lunch and coffee breaks etc. - I'm just fine when I get back home.
If it's a day full of meetings with customers, I'm completely drained and pretty much useless to my family for the rest of the night (at least socially)