What fictional universe is aired on the CW for The Flash?
Arrowverse The Arrowverse is a shared fictional universe that is centered on television series airing on The CW, developed by Greg Berlanti, Marc Guggenheim, Andrew Kreisberg, Phil Klemmer, and Geoff Johns, based on characters appearing in publications by DC Comics. The shared universe, much like the DC Universe in comic books or the cinematic DC Extended Universe, was established by crossing over common plot elements, settings, cast, and characters. The Arrowverse stars Stephen Amell as Oliver Queen / Green Arrow, Grant Gustin as Barry Allen / Flash, Megalyn Echikunwoke as Mari Jiwe McCabe / Vixen, with an ensemble cast leading "Legends of Tomorrow", including Arthur Darvill as Rip Hunter, Caity Lotz as Sara Lance / White Canary, Brandon Routh as Ray Palmer / Atom, Dominic Purcell as Mick Rory / Heat Wave, with Victor Garber and Franz Drameh as Martin Stein & Jefferson "Jax" Jackson / Firestorm. Russell Tovey stars as Ray Terrill / The Ray.
Characters of Smallville "Smallville" is an American television series developed by writer/producers Alfred Gough and Miles Millar, and was initially broadcast by The WB. After its fifth season, the WB and UPN merged to form The CW, which was the second broadcaster for the show in the United States. The series features a regular cast of characters, which began with eight main characters in its first season. Since then, characters from that first season have left the series, with new main characters having been both written in and out of the series. In addition, "Smallville" features guest stars each week, as well as recurring guests that take part in mini story arcs that span a portion of a season. Occasionally, the recurring guest storylines will span multiple seasons.