Stretched between the Outer Planes are three realms that interweave one another, touching upon all realms yet separated from them. These three planes can be viewed as three diluted, thought still vast and encompassing, tributaries of the Ethereal Sea.
The Astral Plane is an open realm filled with silver and bright colors. It is closely aligned with the Material Plane, but also intersects throughout the realms of the gods and in effect touches upon every plane within the sphere of Ashling. The realm itself is a large silvery sky that is the realm which binds all others together, and is a huge open domain. When a mage uses a portal to travel, they are in the Astral Plane before reaching the other side. In simple terms, the Astral Plane is the space between all the other planes which allows transport and travel to occur. Time and gravity have no effect in this realm, and there are practically no native inhabitants to the realm. Travelers can be frequent, due to the nature of the Astral Plane however.
The Ethereal Plane is a realm filled with spirits and dreams. Just like the Astral Plane is closely aligned with the Material Plane, but also intersects throughout the realms of the gods and in effect touches upon every plane within the sphere of Ashling. The realm itself is filled with mists and fogs, and those within the plane can easily spy on those in the Material Plane, albeit things appear blurred and indistinct. The Astral Plane is a much lesser version of the Ethereal Sea- as a lake is a lesser version of the ocean.
The Plane of Shadow is a part of The Ethereal Sea, and is a realm filled with shadows and their ilk. Like the other parts of the Sea, the Plane of Shadow is, once again, closely aligned with the Material Plane, but also intersects throughout the realms of the gods and in effect touches upon every plane within the sphere of Ashling. The realm itself is filled with black and white, and possesses no color whatsoever. It is almost a mirror of the Material Plane, except for the utter lack of color. The Plane of Shadow is highly morphic, in that the landscape frequently changes, especially the further one travels away from their entry point into the realm. There are a number of methods to enter the Plane of Shadow, primarily via magical portals or spells, most of which link the dark realm to the Material Plane. There are some vague links between the Astral Plane and the Plane of Shadow, but nothing exists to link it with the Ethereal Plane.