The Enneagram is a system of personality analysis. 
Basically, in this system there are nine different personality types.  The Enneagram figure looks like a circle, with 9 numbered points around the circumference, and lines connecting various numbers inside the circle.  The Enneagram philosophy is that we are all born with a dominant type corresponding with one of these numbers.  The numbers themselves are neutral, and their ranking is not significant. 
Each type is distinct and has its own unique assets and liabilities.  We can use a questionnaire to determine our type, and then use the Enneagram figure to further describe ourselves and our personality, and how we relate to the other types.  The 9 types are: The Reformer, The Helper, The Achiever, The Individualist, The Investigator, The Loyalist, The Enthusiast, The Challenger, and The Peacemaker.

 

The Enneagram Made Easy