This is mostly a comment of mine on a different post and I thought it might be beneficial if more people saw it.

There is a difference between the common social definition of these two words and the, IMHO, more useful cognitive definition. They are often stated to be related to energy as well. Each definition has their explanations for the sources of said energy.

Everyone is used to the standard definitions of introversion and extroversion. They are used in common psychology often to label people in to one class or another. Introverts are typically classified as quiet loners who sit on the sidelines not speaking and probably definitely have social anxieties. They are said to feel better alone, inside their comfort zone. Extroverts are typically that loud, charismatic, obnoxious, centre of attention we all know and love. The centre of attention part being something they enjoy, and thus a source of energy. This type of version can be changed with appropriate effort. I don't particularly enjoy this definition, though, because it is an excusive label to fuck off on your responsibilities and accept who you are because it is written in the stone. Which is mere bullshit pigeonholing you into your societal role; introverts often are usually beta males and shy girls and extroverts are 'assholes' and the majority of women who actively and overtly seek validation.

Cognitive intro and extroversion is the Jungian definition and is primarily used in Jungian or Meyers-Briggs personality typing. It primarily determines how one seeks and receives information. Introverts look internally first to understand their world before expanding out to a small bubble of people. They are also more likely to feel spent after excessive social interaction because they are used to getting information from within. Extroverts look to the world and people around them first to understand it before resorting to internal means. This source of information is why they feel energized being around others. Because otherwise they feel blind. This type of version is who you implicitly are. It is much more resistant to direct change as this version determines how you naturally react first to new information. It doesn't stop you from reacting any other way or anything if you realize what must be done. It merely determines one's first natural reaction. You are capable of both intro and extroversion as a situation would require. It is similar to a woman's natural hypergamy instinct. While there are many that indulge, there are ones (RPW) who see past that and choose the best option for all given the human situation.

Those are the ones we hope to find. So be such yourself.