In Mystic Astrology the zodiac signs connect to the planes of reality. There is a sign that corresponds to each of the 12 planes within four dimensions. The zodiac belt exists within our etheric bodies transmitting energy from other planes your physical reality. All humans have the 12 signs within them, however not all people are utilizing all these planes.
We each are encoded to move certain frequencies in particular planes. This can be viewed objectively via your blue print - natal chart. A good reason to study your birth chart is to bring on an acceptance of self and an understanding of how your soul has chosen to work with certain energies in this lifetime.
It is important for you to study the sign correspondences to the planes. The purpose of studying Mystic Astrology is to understand how you can access this energy via an understanding of your blueprint. Through spiritual understanding you can achieve a more balanced and harmonious quality of life for yourself.