Plane, does the word mean different dimensions or different parallel universes?

If we have to interpret the parallel universe in a way, it is relatively difficult and complicated. If there is such a thing, then I think it is difficult to explain it clearly according to our current understanding of spatial dimension. Parallel universe, also called multiverse, can be a collection of all higher-dimensional spaces beyond 4-dimensional space. It refers to different universes at the same time and one or more universes at different times. In a word, those scientists understand it this way. There is only one time axis, and all existing universes develop along this time axis. Time is not matter, nor energy, nor a thing. It has no mass, shape and density, and it is only the product that human beings use to measure the development process and laws of events since ancient times, that is to say, time itself is a "nothing" concept. So there is no universe with different time axes and different time axes. These so-called time-point universes are evenly distributed on the time axis, arranged in the order of increasing back and forth, and are static with each other and will not develop separately. This is a different universe with a timeline. I can now observe things billions of light years away through scientific and technological means, while we humans have only been to the farthest moon. In other words, human cognition and conjecture about the universe are far greater than the actual needs. Even if scientists say that there are countless universes like ours outside our universe, we can't prove it in any way. Man's ability to reach the moon cannot prove anything outside the universe. My understanding of the hypothesis of the universe and science is like illiteracy in a remote mountainous area. Although he is eloquent, he can't even write his own name completely. And there is a very important point. With the passage of time and the development of science and technology, human beings will constantly update new theories and arguments to refute our existing scientific viewpoints, such as the original theory of heaven and earth, geocentric theory, Heliocentrism, etc., which were later overthrown.