The aura is understood as the multidimensional energy field that surrounds and interpenetrates the physical body — extending outward in layers of increasingly refined vibration. It is not simply a glow around the body but a complex, dynamic system that reflects the physical health, emotional state, mental activity and spiritual development of the individual at any given moment.
The aura changes constantly — responding to thoughts, emotions, physical health, the presence of other people, environmental energy and spiritual practice. A person in a state of joy, health and spiritual clarity will typically have a large, bright, clear aura; someone in a state of illness, depression or energetic depletion will typically have a contracted, muddy or fragmented aura.
Traditional teachings describe the aura as having seven primary layers, each corresponding to a different body (physical, etheric, emotional, mental, etc.) and to the seven primary chakras. This is the framework we use here, drawn primarily from the Theosophical tradition as systematised by Barbara Brennan.