To try and clarify: A multiverse can contain many different universes with varying laws of physics, and is usually depicted as bubbles (universes) bouncing around in the multiverse. On the other hand, we have parallel universes, or alternate realities, which are formed from the outcomes of every single instance of a particular universe.
Could these alternate realities be depicted as bubbles continuously and infinitely splitting off from one another to create their own separate universes, randomly bouncing alongside the universes with completely different laws of physics?
Or is it possible there is some order to the multiverse, and a universe splitting into an infinite number of alternate realities could more likely be depicted as a fertilized egg cell splitting in two, then 4, then 8, and so on, yet remaining intact to form a single multicellular organism and the multiverse depicted as being filled with many different multicellular organisms, each with their own certain laws of physics?
This is what I meant by two separate entities: The universes which make up the multiverse are represented as multicellular organisms and the alternate realities are the cells "asexually reproducing" within the multicellular organisms, as compared to all universes and alternate realities splitting off from one another, at random, with no order or connection.
Also, I mentioned nothing of the different dimensions that exist so if they are necessary to explain the answer, by all means, teach me.
I also understand that this is all theory, and there is no way to observe and test the existence of a multiverse, alternate realities and dimensions, so I'm just asking what is our best understanding of these subjects at this time.