superclusters are huge groups of galaxies, or, also, Cluster of Galaxy Clusters
most of them contains more than 100 000 galaxies
clusters are huge groups of galaxies, they are containing much less galaxies than superclusters
groups are galaxial clusters that are too small to be called normal cluster. Mostly, 50-150 galaxies in them.
Galaxies (shouldn't be confused with paragalaxies) are gravitationally bound systems of stars, stellar remnants, interstellar gas, dust, and dark matter.
stars are huge balls of heated gas, that made up a ball, because of gravity. Stars are classified by "spectral classes": O, B, A, F, G, K, M. There is also secondary classes: L, T, Y, C, S and D.
In real science, we don't know if other Universes are even existing. However, author of this wiki defined some possible types for another Universes.
Primordial Universe (Up)
Primordial Universe is extremely dense and small (1000 - 2500 light-years wide) universe, that existed at first stages of existance of the Multiverse. Average temperature and density here are really higher than t. and d. of newborn Universes at the stage of it's existence, where diameter was the same. However, all the Primordial Universes gone extinct at the first quintillion years after Multiverse has been born.
Normal Universe (U)
77% of all the current Universes are normal, average diameter of them is nearly septillion light-years wide (at the moment, where age of this universe is equal to current age of our universe).
Dwarf Universe (Ud)
Dwarf Universe is comparatively small universe. If our universe is really 550 billion light-years wide, as Wikipedia says, they, our home universe can be classified as a dwarf.
Ultra-Universe (shouldn't be confused with Ultraverse) is extremely large universe, that became that big, because of its high expansion rate. It's size can bigger than vigintillions (!!!) of light-years. They also can be source of type-I Paragalaxies.
Voidoverse is a universe with extreme expansion rate, billions of billions of times higher that Ultra-Universe's. They could be up to googols of light-years wide. Nothing here survived, this universe is a one big rift of space time.