Earth Prime

Earth Prime (or Earth-Prime) is a term sometimes used in works of speculative fiction involving parallel universes or a multiverse, and refers either to the universe containing "our" Earth, or to a parallel world with a bare minimum of divergence points from Earth as we know it. The "Earth Prime" of a given fictional setting may or may not have an intrinsic value to or vital connection to the other Earths it exists alongside (although it appears to be the case that such Prime Earths -and sometimes the 'central universes' in which those Prime Earths exist as well -are portrayed in fiction to be vital to the existence of the other Earths).