Definition: Most people believe that an extrovert is a person who is friendly and outgoing. While that may be true, that is not the true meaning of extroversion. Basically, an extrovert is a person who is energized by being around other people. This is the opposite of an introvert who is energized by being alone.
Extroverts tend to "fade" when alone and can easily become bored without other people around. When given the chance, an extrovert will talk with someone else rather than sit alone and think. In fact, extroverts tend to think as they speak, unlike introverts who are far more likely to think before they speak. Extroverts often think best when they are talking. Concepts just don't seem real to them unless they can talk about them; reflecting on them isn't enough.
Extroverts enjoy social situations and even seek them out since they enjoy being around people. Their ability to make small talk makes them appear to be more socially adept than introverts (although introverts may have little difficulty talking to people they don't know if they can talk about concepts or issues).
Extrovert behavior seems to be the standard in American society, which means that other behavior is judged against the ways an extrovert would behave. However, extroverted behavior is simply a manifestation of the way an extrovert interacts with the world. Extroverts are interested in and concerned with the external world.