A comic book universe is a fictional world where characters, stories, and events are interconnected across various comic book series. These universes often feature superheroes, villains, and supporting characters, all of whom interact in shared settings. Popular examples include the Marvel Universe and the DC Universe, where iconic figures like Spider-Man and Batman exist. In these universes, storylines can cross over between different titles, allowing for complex narratives and character development. Events such as crossovers and reboots can reshape the universe, introducing new characters or altering existing ones. This interconnectedness enhances the reading experience for fans and encourages exploration of multiple series.