What Would A Parallel Universe Even Be Like?

Our universe has an unimaginable size, but what if she’s not the only one? Our planet is in comparison with people is huge, but the scale of even the Solar system, the Earth seems just a grain of sand on the beach. Solar system, in turn, is also embarrassingly small, if compared with our milky Way galaxy, but similar or even more bulky galaxies in the observable Universe more than a few trillion. But what if universes can be a huge number, and each of them have different laws of physics?