The Great Wheel is the Forgotten Realms cosmology, forget this nonsense retconning from the 3e FRCS. The Fugue Plane is part of Kelemvor's realm. Cynosure is a demiplane, shadow is a major demiplane that touches a large number of inner planes and prime worlds, but still technially a demiplane. Virtually all the "Realms" planes are existing Wheel planes renamed, or are just layers/realms within those planes.
Yes, it's also the Greyhawk cosmology too, because Greyhawk, Forgotten Realms, Birthright, Ravenloft, Planescape, Spelljammer and Dark Sun are all part of the same multiverse (with Ravenloft very hard to get out of, and Athas very hard to get into or out of). As much as WotC tries to forget that was ever the case, it is.
IMC, the "Great Tree" Realms cosmology map exists, as a bit of "clueless prime berk" nonsense plastered up in the libraries and labs of wizards who have probably never been planar, or certainly never travelled around too far if they have, kind of like the horribly inaccurate world maps from the middle ages that had Jerusalem as the center of the world and everything else distorted around it.