The Dimensional Hierarchy

DISCLAIMER: This is just my take on the Dimensional Hierarchy of the Undertale Dimensional Plane, so this might not be canon in any other instance.
It is a commonly known fact that all Universes, even all Multiverses must be contained by something. This is a quick illustration demonstrating what all contains what and just how far containment can actually go.

Universes
"I have a better question for you, Ink. Do you think the Multiverse... is as infinte as your lack of brain?" This is the most frequently knowledged dimension, all of which consist of some form of concept change or another. Most commonly known Universes consist of Underfell, Underswap, Dusttale, Outertale, etc. That's just to name a few of them. A few Universes may sometimes be the birthplace of gods such as Error!Sans, Seraphim!Sans, Reaper!Sans, etc. In a few rare instances, Universes can also be the birthplace of Multiversal beings like Error404, Infected, King Multiverse, etc. Unfortunately, as they are the first and smallest of the dimensions on the Hierarchy, they are also the most frequently eradicated. Not only that, but they are also frequently tampered with; sometimes in beneficial ways, but more often than not in detrimental ways.

Multiverses
"You're the ones who can't see beyond what the Multiverse is. After all, there are thousands of alternate versions. Thousands of timelines in their own universes. Why even worry over a small affected fraction?"

Here we have one of the sturdier dimensions listed on the Hierarchy. These tend to be the birthplace of nearly, if not absolutely infinite quantities of universes. Though many believe Multiverses to be the final container of dimensions, there are far larger containers floating about in the vast Dimensional Plane. Alternate Multiverses are very much possible, it is just a simple matter of an alternate course of events happening within it's Universes' timelines. Although they prove to be much more difficult to destroy than a single Universe, it is still very much possible to completely wipe one out.

Metaverses
"I TELL YOU THIS BECAUSE YOU ARE THE LAST KEY COMPONENT TO RAISING MY LOVE HIGH ENOUGH TO BREAK FREE FROM THIS RESTRICTIVE MULTIVERSE... ONCE I BREAK FREE, I'LL BE ABLE TO CONQUER THE ENTIRE METAVERSE, EVERYTHING WITHIN IT WILL BOW DOWN TO ME... I'LL FINALLY BE THE ULTIMATE MONARCH..."

These ones tend to be one of the lesser known dimensions listed in the Dimensional Hierarchy. Metaverses basically contain alternate versions of Multiverses as explained back in it's own separate sub-article. Some Metaverses may contain Universes that are completely unheard of to other Multiverses and below, more specifically the main Multiverse. Examples of this contain Nucleartale, the Universe in which Contamination was birthed from, etc. Along with this information, Metaverses are also much more difficult to tamper with and/or destroy than Multiverses by an incredible margin.

Xenoverses
Another one of the lesser knowns dimensions in the Dimensional Plane, the Xenoverse. Virtually nothing is known about this type of dimension, but what is commonly known is that they contain a potentially infinite amount of Metaverses. There isn't really much that changes with alternate Xenoverses, they're mainly seen as shields for groups of Metaverses. There has yet to be any form of recorded instance where a being has actually destroyed a Xenoverse before, though this does not mean that there won't one day emerge a being that will actually accomplish such a feat.

Hyperverses
Sorry, I forgot to put Hyperverses in the visual presentation ^ ^;;

Also being one of the lesser known dimensions, Hyperverses pretty much serve the same purpose as Xenoverses do. Hyperverses could also be considered as an extra layering of protection to groups of Metaverses. Though they are usually seen to be enormously more dense than any dimension documented in this page so far, they are also able to be destroyed much like almost every other dimension on the Dimensional Hierarchy. Though, one would need a nearly godlike amount of energy to actually be able to do such, for example; Omnipotent!Sans' Omnithorn form's "ZEUS THUNDERBOLT!" move, which is said to be capable of destroying entire clumps of Hyperverses.

Omniverses
The Omniverse. It is generally considered to be the absolute largest dimensional container, though this isn't the case here. Some Omniverses may have guardians to protect them from destruction, such as Insanity!Tale's GoA, etc. They also contain a potentially infinite number of Hyperverses inside of them, which is why there is such a high demand for protection of these types of dimensions. As such, they are also among the most difficult dimensions to destroy by themselves due to their immense size.

Outerverses
NOW we have reached the absolute finale of the common Dimensional Hierarchy. Outerverses contain a potentially infinite number of almost every sort of common dimension imagineable such as Omniverses, Hyperverses, Xenoverses, Metaverses, etc. They are nigh-impossible to destroy, seeing as they are the final dimension on the Dimensional Hierarchy. Though, there are usually only one of them commonly seen, as anything beyond it is just an astronomically colossal barrier, which will be explained later on in the article.

The Dimensional Barrier
This is the true absolute finale of the entire common Dimensional Hierarchy, it contains only one Outerverse within it. It is one of the most dense objects in all of existence, making it easy to keep anything inside of it safe from anything outside of it. It is speculated that there could be more of these barriers out there, keeping other Outerverses safe from any Outsiders. What are Outsiders, you may ask? They are theorized entities that exist outside of the barrier, many, even some of the Higher Powers, believe that without the barrier, even the least powerful of the Outsiders could potentially disintegrate the entire Outerverse in a mere matter of picoseconds.