Metaverse

The Metaverse is the theoretical container of the simulation which is our Universe. Metaverses exist on a higher plane of existence than the Universe, thus allowing it to simulate the Universe with the Universe still being a "real thing".

Formation
A Metaverse isn't formed via natural processes; instead it is artificial and is built by extremely advanced civilizations most likely at an Omniversal level or higher. Metaverses can take very long to construct, with one of the biggest ones taking over 10 trillion years to finish.

Structure
Metaverses are divided into separate "cells" where a specific -verse or object is simulated. Most of cells are run by creatures inhabiting the Metaverse, with a few being fully automatic.