In speaking of what is often referred to as the 'lower worlds' there are three 'centers' used as primary platforms for Awareness. These centers naturally distort primordial Awareness in relation to their density which is comprised of the various elements found to be held within them. Some of these centers may be less dense and some more dense. This relative density may be considered 'important' as it in large part determines what will be perceived.
Consider this - Awareness/Consciousness/God/Spirit/Allah/Life Is All that there IS. This can be likened to a Great River. This River extends in all directions, in all dimensions without duration. This River is the ground substance in which all 'beings' interact and upon which all 'beings' seemingly live and die. This River has many names and many faces and while each of these exist as the River, the River doesn't exist as them.
Upon the surface of this Great and Powerful River eddies and small whirlpools get created from interacting currents which arise and resolve with natural spontaneity. These whirlpools create a spinning kinetic and centripetal force upon the surface which, and as they become grouped together, harmonize into a combined 'local wave effect.' This local harmonization becomes the context of a 'local body.'
What we often call 'centers' may be seen as little whirlpools on the surface of the Great River of Life. A few of these whirlpools working together can generate a combined ripple effect that can be likened to dropping several rocks into a pond close to each other. When the rocks are dropped close to each other the ripples moving outward eventually harmonize and become conjoined creating a local self construct, border, or boundary. This local border is often spoken of as the aetheric body, aura, or the energetic boundary of the local self construct.
These little spinning pools, at this point comprised only of pure Awareness and now being bordered become attractive due to their centripetal nature. They begin to draw and attract material(s) from the surface that they have some affinity with (in relation to their karma, vibrationally speaking). This material, coalesces and builds the various aspects of 'form', elementally speaking.
To further the mental imagery - Imagine we are sitting in our bath tub and we let the water out. A whirlpool arises on the surface of the water in relation to the energy being exerted on the surface from far below (think about how far this actually goes - it is much farther than the bottom of the tub). Now imagine that we would never run out of water, our little whirlpool will continue to exist as long as the forces from deep below the surface continue to create it.
Lets go back to the surface of the tub. Our little whirlpool is happily spinning along. Its constancy and relative stability imbue it with the power to be attractive. It will bring 'things' towards it and that which moves towards it begins to give it shape and texture. The surface becomes 'defined; by the materials it holds within its circulating centripetal nature. These material items, take on the energy of the whirlpool to some degree and being enlivened by its kinetic energy become attractive themselves. This goes on with denser and denser materials until the little vortex of whirling energy has been completely veiled by the layered stratum of materialized karma.
Now expand the image back to the Great River of Life. Just like our tub, but with no bounds or borders, upon Its mighty surface there are an infinite amount of spinning vortexes. These little constructs or bodies of relative sentiency have a variety of whirlpools within their 'local construct.' Some have 3, some 5, some 7, some 9, some 13, some 108, etc. No matter the number, they gather materials in relation to their spin or frequency of spin and this material builds upon itself the great fortress that we call our body, or vehicle of manifestation.
We could speak a great deal about the vehicle, its characteristics, its make-up, etc. We could write books about the nature of the etheric body, its centers of force and the channels and smaller centers that comprise it. But maybe most importantly we can step away from the vehicle for a moment and remember that what we call 'our vehicle' is really just a moment of distortion on the surface of the Great River of Life. The energy that creates, maintains, nourishes, enlivens and activates each and every spinning pool is the same. We may, for a moment, take on the perspective of an 'identity' built upon the surface, but these spinning pools will only last for a second before they destabilize and send their collected material back out into the great current of the River Itself imbued through new experience, through suffering, hardship, through pain and under great pressure.
Additionally, every vehicle in manifestation is a shared experience of Life Itself. There is no body that is separate from it, as all bodies exist within it, and as It. The materials that comprise our 'local bodies' being collected from other aspects of our greater self, may also seem diverse, but essentially are made of 5 or 4 depending.
The point here is not about etheric mastery. The point is about Oneness and whether we can behave in relation to our true nature or not?