Introvert vs Extrovert

Which are you? Could you be some of both? What makes one an extrovert? What makes one an introvert? When are you most comfortable -- alone or in a group? Do you function smoothly while in a group and then breathe a sign of relief once you are away and have some time alone?
Do you come away from group activities invigorated and enthused? What kind of profession would better suit each personality type?
I taught school for many years-- a profession seemingly suited for the extrovert. I am quite introverted truthfully. Often teaching wore me "slap out!" I was ready for plenty of quiet time at the end of the day and sometimes before. Fortunately for me I came home each day to a very quiet environment where I could sit and ponder or just rest from all of activity of mind and body.
Sometimes it is very difficult to know whether folks are introverted or extroverted. Our scales of measure may be out of kilter or perhaps we truly do not understand the characteristics of each. Or even more importantly maybe we do not know each other well enough to make the call. Understanding personality types can make a world of difference in getting along with others including one's chosen mate. My husband was more of an introvert. It did not take me long to realize that it didn't pay to push him to talk when he didn't want. However, I learned quickly that he would open up and share his thoughts with me when he felt the need. Fortunately, I had received worthy training earlier in how to listen without intruding.
I. on the other hand, need to talk through and resolve issues that bother me immediately. He often was my sounding board and sometimes I would ask him to look at an issue and tell me whether I was blinded by the forest and trees. I valued his opinion We both fit the category of introverts but with very different styles.

Who knows what determines personality traits other than the gene pool with which we are all blessed when formed in the womb! I am a believer that our understanding and determination to work with those traits make all of the difference in relationships.