“…We find that the terms introvert and extrovert (originally spelled extravert) were popularized by Carl Jung in the early 20th century. Unfortunately, their meanings got confused between then and now, and we started thinking that everyone belongs to one camp or the other. But actually, Carl’s point was that these are the very extremes of a scale.
Which means that most of us fall somewhere in the middle.
There is no such thing as a pure introvert or extrovert. Such a person would be in the lunatic asylum. – Carl G Jung…
… Introversion and extroversion actually relate to where we get our energy from.
Introverts (or those of us with introverted tendencies) tend to recharge by spending time alone. They lose energy from being around people for long periods of time, particularly large crowds.
Extroverts, on the other hand, gain energy from other people. Extroverts actually find their energy is sapped when they spend too much time alone. They recharge by being social…”
Sourced from here, where you’ll find a helpful overview for a general reader. Thanks to my Canadian friend Len for bringing it to my attention. The accompanying image is sourced from the article linked to above.