Often people get confused between the true sense of the words introversion, extroversion and anxiety.
Introversion basically is the preference for solitude over company. The individual wants to be left alone and enjoys his own company.
Extroversion basically is the preference for company over solitude, an exact opposite of what introversion is. An extrovert individual wants other peoples' company and generally dislikes being alone.
Anxiety is the fear of socialising. It is when the individual fears going out or be seen in the public. It is a mental disease.
People should always be mindful to not conflate introversion with anxiety. Because introversion is not a disease that needs to be and can be cured with/by extroversion but anxiety is.