There a various ways of mapping out different planes of existence. I am not an expert of any of them, and this is really only mentioned here to make sure you are at least marginally aware of commonly used maps. Various numbers of planes are referred to in esoteric literature, often up to seven, but to keep things really simple we can say that there are three bands of reality:
The Physical plane is the visible, solid manifestation, and the exerted effort and emotion connected with it. The Astral plane is non-physical. It can be thought of as the template for what is manifested in the physical. But it is also a realm in itself that one can operate in. The Spiritual plane is beyond a need for form and looks much less like the physical world than the astral does. Each of these major planes can again be divided up, as mentioned. Various traditions use different names for the different sub-divisions.
One's physical body has counterparts existing in different planes. The manifestations in the higher planes are often referred to as subtle bodies. In various traditions one would refer to an etheric, an emotional, and a mental body as part of the physical plane, and other subtle bodies as part of the higher planes. The ones closest to the physical are roughly in the shape of the physical body, and act as templates, governing the state of the physical body.
The physically oriented subtle bodies are intimately tied to the physical body. As to the astral bodies, they are usually also in the shape of the physical body and located in the same vicinity. However, they can also under certain circumstances move away from the physical body which partially accounts for astral travel, or out-of-body experiences.
Transformational processing deals largely with the planes and bodies and energy phenomena beyond the strictly physical. However, typically we do it without much esoteric terminology. But the whole basis of the Transformational Processing System (TPS) is that we change the blueprints and assume that the physical manifestations will change accordingly. That means that at least we are working with the emotional and mental planes. And techniques like polarity integration or soul retrieval could well be said to take place mostly in an astral realm.
Overall we are also working on getting the different parts of the person aligned, and bringing about more contact and linkage between different levels of awareness. So, in this context we are working on bringing the physical aspects of the person into contact and alignment with the astral and spiritual aspects.