when was it launched?
October 2012
Arrowverse
October 2012
when does the flash show up in arrow December 2, 2014 is this a film? It is an Arrowverse crossover event what do you mean by this first term you used in your answer? The Arrowverse is an American media franchise and a shared universe that is centered on various interconnected television series
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Arrowverse [SEP] Introduction
The franchise began with "Arrow", based on the character Green Arrow, which debuted in October 2012. It was followed by "The Flash" in 2014, and the animated web-series "Vixen" in 2015. The franchise was further expanded in 2016, when in January of that year a new series titled "Legends of Tomorrow" debuted, starring characters that originally appeared on both "Arrow" and "The Flash". Later that year, the CBS series "Supergirl", having already crossed-over with "The Flash", was moved to The CW for its second season, where it has remained since. A second animated web-series, "", was released in 2017, which followed Ray Terrill / The Ray, who would make a live-action appearance during that year's crossover event "Crisis on Earth-X".