Multiverse

A Multiverse is a finite or infinite collection of Universes, each with different laws and properties.

Formation
Multiverses are formed differently than Universes. Multiverses with a finite number of Universes are usually formed by a group of Universes grouping together with gravity. The Multiverses with infinite Universes are mostly created by entities from outside the Multiverse.

Structure
Multiverses are more likely to have a loose structure, with many voids and spaces between the Universes and other objects that it contains.

Parallel Universes
Each of the separate Universes inside a Multiverse are known as Parallel Universes. They usually are closely related in terms of space, time, dimensions, properties, contents, and more. Parallel Universes will also sometimes have different laws.