A Composite is a Partner Horoscope that combines the attributes of two people to predict their strengths and weaknesses. We plot the midpoints between similar pairs of planets and other special points of the natal horoscopes and we derive the composite chart.
In this instance it is not the comparison of two Birth Horoscopes like Synastry, but the creation of a new, virtual Horoscope. The purpose of Composite analysis is to establish the qualities of two people when they are combined together, thus to examine how they are likely to interact together when working as a team.
The team could be as colleagues at work, or in a union of
some sort such as a marriage or business relationship. This chart will
give an insight into establishing where the qualities of each person are and
where there is likely to be competition between two people to take charge of a
given situation. A Composite analysis would highlight who has the
strongest attributes in a given situation so as the two people can best decide
to leave responsibility to the person who is most up to the job.
In summary of the differences between Synastry and Composite Charts;
A Synastry Chart primarily views one person to another in a relationship. A Composite chart is a view of the combined relationship.