The CW DC universe has officially ended with the ending of their Superman and Lois series. For those who doesn't follow, the CW network have their different shows based on DC characters. These shows gets crossovers with the other shows, making them in the same reality. I am not using universe as these shows could be on a different universe but within CW. Anyways, the CW universe started with the Flash, then you get Supergirl and Arrow. These shows have different level of dark, as in some shows are darker with some violent more than expected. As these shows are mainly for adults, the ratings are there. As of now, the CW universe is the biggest DC universe for live action, much like what Marvel does for their MCU. For the DC comics fan boys and fan girls, do not expect the CW shows to stick with the comics source material. There are changes done to them that some fans may find it unacceptable. These changes, such as race swap, gender change, costume changes, characteristic changes as well Who's who in a different show then expected. Such as the West family in the Flash, they are now a black family. A new character, not of in the comic is part of Firestorm. Mr Terrific is a sidekick level character and is gay. The Atom looks like Iron Man more than the what we know of shrinking in size. Batman villains now become Green Arrow villains and Oliver Queen acts like how Batman would be. Watch the shows and enjoy them. You don't need to watch every shows to get the story.