DC TV universe explained – How The Flash, Supergirl, Arrow and Earths 1-3 fit together

How Supergirl, The Flash and Arrow fit together.

Crisis on Earth-X - Wikipedia

DC TV universe explained – How The Flash, Supergirl, Arrow and Earths 1-3 fit together

The Flash (season 3) - Wikipedia

Earth-Prime Explained: How Crisis on Infinite Earths Changes the DC Multiverse - IGN

Crisis on Infinite Earths: The Arrowverse's Earth-Prime explained

Roy Harper - News - IMDb

Earth-Prime Explained: How Crisis on Infinite Earths Changes the DC Multiverse - IGN

Superman and Lois” Ordered to Series at The CW — “Supergirl” Spinoff – TVLine

What is your favorite show in the Arrowverse? : r/Arrowverse

In the DC Comics Universe, does 'Arrow' exist on “Earth-One” with “The Flash,” “Supergirl,” etc.? Or is that all just part of the same world/universe? - Quora