Although I have always been social, I began noticing in college a feeling of depletion after spending time with a group of people. As a result I began gravitating toward one-on-one social situations or being alone. I generally seek quiet environments with a minimum of distractions and find pleasure in many solitary activities:reading, writing, drawing, etc..Yet, this does not discount the joy I find engaging in good conversation.
I recently heard someone describe the energy she derived from large social affairs. Although I can appreciate her sentiments, it is difficult for me to empathise.
Although I tended to think of an introvert as someone who is shy, it is now defined as one who generally prefers solitude to social situations. The woman mentioned above would likely be considered an extrovert. If neither describes you, perhaps the term ambivert is most suitable, a combination of the two.
Such labels are interesting, particularly as they evolve over time, but they are probably best used to provide some insight and acceptance of ourselves.