In other words, Barry Allen no longer needs to use an extrapolator to see Kara and vice-versa.

Apparently, this was always the end goal of Crisis on Infinite Earths.

Even though in the comics, Earth-Prime is our Earth, I just personally like the sound of Earth-Prime.

Legends of Tomorrow

Colin Bentley/The CW

So all of the CW [superhero] shows will be on the same Earth.

In fact, the Arrowverse starts embracing the possibilities of Earth-Prime in tonights episode.

And Earth-Prime isnt the only change.

Earth-19:Home of the shortlivedSwamp Thingseries on DC Universe.

Earth-9:Home of DC UniversesTitans, which was renewed for a third season last year.

Earth-96:Brandon Rouths Man of Steel fromSuperman Returnlives!