Esoteric Astrology is a branch of astrology that is focused on spiritual purpose. Although it uses your natal chart (just as it does in the more common exoteric astrology), esoteric astrology uses a different set of rules for the planets and houses. Most esoteric astrologers, including myself, tend to combine the more grounded exoteric astrology with esoteric interpretations to give you a more comprehensive understanding of how you can put your spiritual purpose into practical use in this lifetime.
Within Esoteric Astrology is another branch called The Seven Rays. This information takes you beyond our solar system to a universal perspective, a place called the Great Central Sun by people working with the information provided by the mystic Alice A Bailey and Master Djwahl Kuhl. The people most drawn to work with esoteric astrology and the seven rays are consciously aware that they incarnated to be of soul service. The esoteric astrology consultation provided by Mark is more easily understood by people who already have a basic understanding of their natal chart.
For more information: The Seven Rays Explained (PDF handout)