Comic book universes are fictional worlds where characters, stories, and events are interconnected. These universes often feature superheroes, villains, and various supporting characters, all of whom interact within a shared setting. Major comic book publishers like Marvel and DC Comics have created expansive universes that include multiple series, crossovers, and alternate realities. Within these universes, storylines can span decades, allowing for character development and complex narratives. Events such as Crisis on Infinite Earths or Infinity War can alter the landscape of the universe, impacting numerous characters and their stories. Fans often enjoy exploring these interconnected tales through comic books, movies, and television shows.