Comic book eras refer to distinct periods in the history of comic books, each characterized by unique themes, styles, and cultural influences. The main eras include the Golden Age, marked by the introduction of iconic superheroes like Superman and Batman, the Silver Age, which saw a resurgence of superhero stories and the creation of characters like Spider-Man, and the Bronze Age, known for more complex narratives and social issues. The Modern Age follows, featuring diverse storytelling and a focus on character development, with notable works from creators like Alan Moore and Frank Miller. Each era reflects the changing tastes and societal values of its time, shaping the evolution of comic book storytelling.