The Obsidian Veil is the scholarly name for the physical place where existance takes place. It consists of three parts: the Warp (the material universe), the Weft (the conceptual universe), and the Veil between them.
Arguably, there is one other part of the Obsidian Veil, but that realm is dark, enigmatic, and immune to all forms of science and magic discovered thus far in the Obsidian Veil. This other realm is known as the "Darkness Between the Stars", or the "Void", and it exists both outside the Obsidian Veil, and between it.
There is little to say about the Void, as little is known. But whatever it is, it and all its inhabitants and powers are antithetical to light, life, and existance itself. You have been warned.
"Warp" and "Weft"
The Obsidian Veil, also called "the universe" can be understood as being made from a fabric woven from strands of energy. This is not literally the case, but it is a common metaphor to help metaphysicists understand the Veil.
The Veil, as with any woven material, consists of three parts. The "Warp" or "Top"; the "Weft" or "Bottom"; and the "Threads" themselves.
The Warp (a.k.a. Material World)
The laws of physics, such as they are, apply normally within the Warp of the Veil. Planets are generally spherical as gravity tends to cause a spherical shape. Stars are giant burning balls of fire and plasma. Etc. Because of its familiarity, many scholars simply call the Warp the "real world" or the "material world".
The Weft (a.k.a. Astral Sea)
The Weft, or "Astral Sea" (see below) is the source of most known magic in the Veil. While phenomena like gravity, light, and time typically function similarly in the Weft as in the material world, they are much more flexible. Locations take on attributes to reflect the events and ideas associated with them, and even with the corresponding locations in the real world.
It is not uncommon for the Warp and Weft to overlap, creating strange phenomena, or even bridges between the two (often called "thinnings", which is short for "thinning of the Veil"). These "thinnings" tend to happen in places of conceptual importance, such as natural wonders, sites of great battles, and the like.
The corrollations are not one-to-one, however, and both distance and time in the Weft can vary widely compared to the Warp. Two places that are next to each other in the real world might be far apart in the Weft, and places far apart in the real world might be adjacent in the Weft.
It is worth noting that the Weft is not limited to the Astral Sea, but the Astral Sea is such a large part of the Weft that the two titles are often used interchangeably. Similarly to how you might call a massive swath of water an "ocean" even if there are technically some islands there too.
