The “many worlds” interpretation of quantum mechanics suggests that when a measurement is made on a particle, all possibities of the particle play out in different universes, such as the wording also called “parallel universes”. If you were wondering why or how these stuff exist well it’s some theories such as “The many worlds” theory scientists also suggest that there may be an infinite number of universes alongside our own. According to Everett, observing parallel universes causes a split in the universe. The universe duplicates splitting into multiple parallel universes for each state of multiverses If you think about it these parallel universes are more like dreams as they mimic the multiverse concept by presenting alternative scenarios and other stuff referring to the uncertainty and multiplicity of the multiverse theory suggests. This shows just how similar dreams are compared to the multiverse and parallel universes. Dreams are also portals to parallel universes because dreams can be more vivid and full of emotion. Although parallel universes and dreams seem similar, they are different from each other by, in dreams it filled with allot more emotion and other stuff while your asleep, but the multiverse is just infinite universes that are somewhat like that phrase.