A plane referred to an independent universe. Why did the plane world in the novel seem like a different galaxy in the universe?

The plane world in novels usually referred to an independent universe that was independent of the real world but had some connection. Different from the real world, each world in the Planar World was independent, with its own rules and history, as well as its own resources and creatures. These worlds were often depicted as different galaxies or planets that were far apart but could be connected in some way. This was because the purpose of creating plane worlds in novels was to make the story more colorful and provide more adventures and challenges for the characters. By describing the plane world as an independent galaxy or planet, the author could let the readers imagine that these worlds had their own stars, planets, satellites, planetary systems, etc., so as to better understand the rules and structure of this world. In addition, depicting the plane world as different galaxies or planets could help readers better understand the various technologies and magic that appeared in the novel. For example, the technology in a certain plane world might be similar to science fiction movies in the real world, but in some aspects, it was more advanced and mysterious. By describing this plane world as different galaxies or planets, readers can better understand the origin and characteristics of these technologies and magic. Therefore, the plane worlds in the novel were like different galaxies in the universe, providing readers with a more colorful and imaginative literary experience.