Wyrlde exists in a closed off shell of spacetime that is the size of a solar system and surrounded by tens of thousands of various burning gas clusters that are usually called stars.
It was removed from the space-time continuum that it was once part of and sealed by the combined power of the Powers That Be in what ultimately proved to be a mistake.
This space is considered to be the Known Universe and is normally referred to as the Ephemeral Dimension of the Plane of Mortality, or the Mortal Plane.
Mortality rests at the nexus of several other planes, created by the overlapping, competing, and commingling of those forces that the planes represent. All the Planes occupy the same space, the same moment, the same whole, and the same world, but are different realities that are called Dimensions, with each Plane having four Dimensions and the space between the Planes and the Dimensions having even more dimensions. Planes are essentially containers of a sort for the Dimensions, not distinct places themselves – They are more than a mere tool for grouping, having an impact and a kind of influence on the Dimensions within them that creates a commonality, but they are not truly a place one can go, in and of themselves. Only the Dimensions can be visited.
Each plane is a stack of four distinct Dimensions, or realities, each coexisting with other Dimensions, and the whole creates a complete multiverse – and within the greater Cosmology they are merely a part of a larger one. Should you pass into to one of the Dimensions or cross the Veil and go beyond the Pale, you will still be on Wyrlde, in the same place, but the place will be different.
There will be other people – possibly even another you, in every Dimension in every Plane and that’s 28 Dimensions that exist in total that we know. When you cross into any of the other dimensions from the Ephemeral, the Powers of that Dimension are the beings we call Denizens who are the children and descendants of the Powers That Be from the Plane of Mortality. So, should one Journey to the Infernal Plane, the Powers that Be are all Devils, Demons, and Hags, still subject to the greater oversight of the Powers of the Plane of Mortality, who created the Cosmos.
In some Dimensions, there is no magic at all. I have watched a person die and seen a Power snatch that same person from a different Dimension and put them back exactly where the previous them was. This is because all the Dimensions are reflections, echoes, shadows of our own; sometimes off a little, sometimes off a lot.
Throughout all these many realities is The Pale, acting as a kind of permeable borderland in which dwell the Elementals and the Veil Gates that both brings them together and keeps them separate. Crossing this is going Beyond the Pale.
To move among the Planes requires one to deeply understand The Veil and The Pale.
