#inborn!error

So the Realms, as a whole, can be broken down into three main categories. They can blend into one another, (EX the digital realm just literally being "behind the screens" of the physical/standard realm) though they all have their own typical boundaries of the "reality" and the state of inhibitability.

The Physical (or Standard) Realm:

The physical AUs as a whole-- or just the basic aus in a nutshell. This is where things will typically be set, and Ink is the general "guardian" of this realm and executes his job by keeping their codes in check & renewing it as necessary. Consists of almost all of the AUs, from mainstream (UnderSwap, UnderFell, XTale, basically any "original" idea for an au) to fragments of timelines. (Unfinished AUs, such as UnderTone, or "copy pasted"/crossover AUs like the SwapFells/FellSwaps, AUs such as Dust!Outertale where two stories overlap, etc)

** (I say almost all because I believe Error's anti-void is considered somewhat an au and the anti-void is where the Digital realm is set....)

This is generally the one most people can "access" without special conditions of their state of being (like being asleep for the Dream Realm) or the extent of their soul/code. (ex: Error being specifically able to operate the Digital Realm due to the nature of his code) It's the standard place in which humans and monsters live!

The Dream Realm:

Kind of sums itself up in the name-- where humans and monsters have the potential to slip into via sleeping & in turn dreaming. Wow!!! Not a lot of people are able to slip into it & bend it to their will/find a way to orient themselves through it the way Somn & Sol can, typically only slipping into such and having a general feel of causing "fever dreams" upon being remembered by whomever falls into it temporarily. It's very fluid and I personally imagine it to be pictured as watercolor painting (and paintings as a whole, if that makes sense?)

As stated above, not many people have the ability to influence the extent of the dream realm & their physical bodies tethered to it whilst sleeping besides the Dreamtale twins & any other member of the multiverse with similar abilities & status of their code (so, empath-related magic & being a minor immortal creature to a literal god, which no others will be identified besides Sol/Somn. They're out there tho. Just veeeery uncommon.)

Though travel through it can vary from one person to another, Somn has found a way to efficiently do so via inserting himself into someone's dreams (he can't. do that easily with anyone. It takes more effort on his end the less connected they are to the corruption) and then getting them to regurgitate him from their system (aahem v0mit him up)

Sol has yet to master a way to travel through it & prefers not to execute it in a manner his brother does, so instead they use their influence over the dream realm to sway the physical state of others. (Think like mantis from Guardians of the Galaxy.)

Ink & Error have a slight ability to "travel" in and out of the Dream Realm, more or less just being able to take a peek and coherently understand what's happening for whoever their focus lands on.

Very limited but most likely the one we'll explore quite a bit when it comes to scenes specific to the twins. ◡̈

The Digital Realm:

Last but certainly not least, the Digital Realm! This is literally just. The internet spat into an entire domain able to be traveled through & lived in by specific types of beings such as Error & Fresh (which are the two main named ones- there's a few others, of course, but they're only anonymous "viruses" on Fresh's beginning level of influence, only serving purpose to clean crumbs of code connected through devices of the physical realm) Ink is, of course, technically able to slip into the realm but only does so to lend a hand to Error every now and then.

It's strictly code-based, being basically the multiverse's data center for au statuses and suchlike, and devices only being a "window" or expansion of the realm which happened to extend the reach of the realm & allow it to blend into the physical realms boundaries. @r0ssx-x described it perfectly-- as an archive for Au info, kinda like a wiki version of the webbing in Error’s void. It's controlled and operated by Error, who monitors any viruses or issues in coding sequences, using physical webbing (in void) to keep track of corrupted or ruined aus. The viruses which reside in the Digital realm are able to influence the physical realm's devices in a variety of manners, a main example of such being Fresh acting as a "desktop pet" for users & constructing websites to communicate & such with the physical realm.

Error also monitors the influence the viruses have on the physical realm, being able to interrupt & block whatever they're doing in the moment if he considers it too far or potentially damaging to the AUs code. (His interruption would appear as Error popups on peoples screens LMAO) He's also the only one able to freely hop about from the Digital realm to the Physical-- if Fresh wishes to, he'd have to find a way to build his code and then essentially have someone allow him to USB-style "download" his code to them and boot them out of their physical state.

The Digital Realm is only really able to be comprehended in a spiderweb-like format, as that's how Error organized it throughout his "life" of building it up from the disorganized mess of the less developed version of Inborn's multiverse into what it is "today."