Okay, so basically, I wanted to sort of explain what exactly the infinite universe is. I thought it would be easier with a picture reference, so I decided to make a separate story where I can have the reference picture as the story picture. Anyway, here's the explanation I gave at the end of Chapter Two:

The Enchanted Forest and all other CANON realms are like planets in a galaxy, just like how Earth, Mars, Saturn, et al. are all planets in the Milky Way Galaxy. The name of the "galaxy" that the Enchanted Forest and all other CANON realms are in is called the Magic System. Think of it as having a membrane that surrounds the different realms in OUAT. In another membrane is Narnia and its real world. The membrane surrounding this is called the Narnanian System. Likewise with Yggdrasil. The Yggdrasil System is made up of the Nine Realms and is surrounding by a membrane. One of the realms, Midgard, is a System within a system and it is called the Midgard System or the World of Heroes. The comparison for that is there are galaxies containing solar systems which contain planets. The galaxy being the Yggdrasil System, the solar system being the Midgard System or World of Heroes, and the planets being the realms inside the Midgard System or World of Heroes.

Expanding on that a little. Imagine the universe is outer space. Easy enough, right? Okay, so you know how there are solar systems in the universe? Perfect. The Land of Many Realms, the Narnanian System, and the Yggdrasil System are solar systems in the universe. Now lets break it down by system.

The Land of Many Realms: NL- Neverland, LWM- Land Without Magic, O- Oz, W- Wonderland, EF/M- Enchanted Forest/Misthaven, A- Arendelle, LWC- Land Without Color, and LUS- Land of Untold Stories. The orange barrier between LUS and everything else is because you need a key to travel to that land. There is a tiny purple barrier that allows for Lucy's wardrobes or magic beans or other magical ways of transportation between realms, but it is hidden behind the realm and very difficult to get to. Arendelle is connected to EF/M because you can travel from Arendelle to Misthaven by boat and no magical transport is necessary.

The Narnanian System: N- Narnia and RW- Real World. Similar to Arendelle and EF/M, the real world is connected to Narnia closely and constantly through the wardrobe.

The Yggdrasil System: A- Asgard, Alf- Alfheim, V- Vanaheim, Mid- Midgard, Mus- Muspelheim, Nif- Nifelheim, J- Jotunheim, S- Svartalfheim, and H- Helheim (my mistake. Helheim is another place within Yggdrasil. This should be Nid- Nidavellir). The rainbow bridge is the Bifrost, or the way to travel the nine realms. If you know Norse mythology or have seen or read Thor, you probably understand all this easily. Asgard is home to the Asgardians, Alfheim is home to the light elves, Vanaheim is home to the Vanir, Midgard is home to humans and humanoid species, Muspelheim is home to fire demons and dragons as well as Surtur, Nifelheim is home to unknown species but is where the region Helheim is located, Jotunheim is home to the frost giants, Svartalfheim is home to the dark elves, and Nidavellir is home to the dwarves.

Within the Yggdrasil System, Midgard has its own system. It's called the World of Heroes or Midgard System. Besides Earth (Midgard) there is of course Mercury, Venus, Mars, Jupiter, etc. There are also more planets in the system that will be revealed in a later chapter of Once Upon A Time Travel: The Infinite Universe.

If you have any questions, please feel free to ask. I hope this clears a lot up!