Answer:
A parallel universe is a universe that sits alongside many other parallel universes in what is known as a universe. It is a theory, which means there isn’t much evidence to back it up.
In this theory, there is an infinite number of universes, so yes, there is one with doppelgangers of everyone on earth. There is one where an asteroid hits the earth every year and wipes out any possible life in the process. There is another where the earth doesn’t exist.