2.  The second plane, sometimes called the Inner Plane or subjective world, it is an alternate dimension both coincident to our physical world and extending beyond it. Some believe it extends to other planets and allows for astral travel between them. 

It is that level of concrete consciousness between the Physical/Etheric, the sphere of ordinary consciousness, and the Mental and Spiritual levels. It is where dreams, vision, and imagination are experienced and magical action shapes physical manifestation.