Sometimes Science is stranger than fiction. Parallel universes are the Multiple Universes which are hypothesized to be existing. These alternate Universes concept is supported by Physics, Astronomy, Cosmology, and Religion. They are conceived as coexisting alongside our own universe, though undetectable for the present.
A wormhole is a path which connects between two parallel universes. It is given the name as a worm digs through the center of an apple and gets to the surface of another.