Question

what is multiverse and what is an universe?

Answer 1

this is the answer from google

Answer 2

The multiverse[1] is a hypothetical group of multiple universes including the universe in which we live. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, the physical lawsand the constants that describe them.[2][3][4][5]The different universes within the multiverse are called "parallel universes", "other universes", or "alternative universes".[6][7][8]



In Dublin in 1952, Erwin Schrödinger gave a lecture in which he jocularly warned his audience that what he was about to say might "seem lunatic". He said that when his equations seemed to describe several different histories, these were "not alternatives, but all really happen simultaneously".[9]

The American philosopher and psychologist William James used the term "multiverse" in 1895, but in a different context.