That is normally how it is characterized. But certain social scientists define it a different way:
If it takes more energy to be social than the energy one receives from being social, that person is an introvert.
If one receives more energy by being social than it takes, that person is an extrovert.
Many people are not stuck in either tendency forever. Sometimes, people can change back-and-forth throughout their lives.
IOW:
Here is how it manifests in me:
I'm not good at "mingling." This is usually the common setting that people socialize. When I was single, I was never good at "dates." There were only two exceptions to that rule. My (now) wife was one of them.
I have always been good in "forced interaction" like when we go to work, or a class. I've excelled at public speaking and group discussions (both as a leader as well as a participant).
"Well, aren't social gatherings/mingling just a group discussion?"
Yes, I suppose they are. But usually a "classroom" situation puts some order and focus to it. This very forum has some "order" to it. In a group where you're mingling, there is no order to the discussion. You can't really get your point across or fully explore a question in the midst of chaos.
It seems that for both Vort and me, the question is this: Is it energizing or enervating?
For me, I change back and forth because of the type of encounter. If it is ordered, it takes less energy from me. If it is chaotic, it takes more energy from me. Additionally, the individual(s) I'm with will also require more or less energy to be around them.
What about just playing?
I never learned to play when I was young*. So, unfortunately, I see games as a competition. And that's not why people play games. I don't know how to "play". So, it is always enervating.
If it is an actual competition (OTOH) then I'm in.
*I did play with my kids when they were younger. But that was where there was a special dynamic that we just don't have in the world of those over 10. I simply can't apply that same attitude to peers.