The Arrowverse is a shared universe of television series based on characters from DC Comics. It began with the show Arrow in 2012 and expanded to include popular series like The Flash, Supergirl, and Legends of Tomorrow. These shows often feature crossover events, allowing characters to interact and share storylines. The Arrowverse is known for its interconnected narratives and character development, appealing to both comic book fans and general audiences. It has introduced various iconic characters, including Green Arrow, Barry Allen, and Kara Zor-El, while exploring themes of heroism, friendship, and sacrifice.