A comic book or comicbook (often shortened to simply comic and sometimes called a funny book, comic paper, or comic magazine) is a magazine made up of narrative artwork in the form of separate panels that represent individual scenes, often accompanied by dialog (usually in word balloons, emblematic of the comic book art form) as well as including brief descriptive prose. The first comic book appeared in the United States in 1934, reprinting the earlier newspaper comic strips, which established many of the story-telling devices used in comics. The term "comic book" arose because the first comic books reprinted humor comic strips. Despite their name, however, comic books do not necessarily operate in humorous mode; most modern comic books tell stories in a variety of genres. The Japanese and European comic book markets demonstrate this clearly. In the United States, the superhero genre dominates the market. Horror stories Since the introduction of the comic book format in 1934 with the publication of Famous Funnies, the United States has produced the most titles, with only the British comic and Japanese manga as close competitors in terms of quantity of titles.

The comic book industry in the U.S. markets the majority of its output to young adult readers, though it also produces titles for young children, as well as catering to adult audiences. Cultural historians divide the career of the comic book in the U.S. into several ages or historical eras: Proto-comic books and the Platinum Age Golden Age Silver Age Bronze Age Modern Age Comic book historians continue to debate the exact boundaries of these eras, the terms for which originated in the fandom press. Comic books as a print medium have existed in America since the printing of The Adventures of Obadiah Oldbuck in 1842 in hardcover—making it not only the first known American comic book, but the first American graphic novel as well.

The start of the Modern Age (occasionally referred to as the "Iron Age") has even more potential starting points, but is generally agreed to be the publication of Frank Miller's Batman: The Dark Knight Returns graphic novel and Alan Moore's Watchmen by DC Comics in 1986, as well as the publication of DC's Crisis on Infinite Earths, written by Marv Wolfman with pencils by George Pérez. Comics published after World War II in 1945 sometimes get labeled as products of the "Atomic Age" (referring to the dropping of the atomic bomb), while commentators[who?] sometimes refer to titles published after November 1961 as belonging to the "Marvel Age" (referring to the advent of Marvel Comics). However, the secondary literature refers to these eras far less frequently than to the aforementioned designations. A notable event in the history of the American comic book came with the psychiatrist Fredric Wertham's criticisms of the medium in his book Seduction of the Innocent (1954), which prompted the American Senate Subcommittee on Juvenile Delinquency to investigate comic books. In response to attention from the government and from the media, the U.S. comic book industry set up the Comics Code Authority in 1954 and drafted the "Comics Code" in the same year. Underground comics Main article: Underground comix In the late 1960s and early 1970s a surge of creativity emerged in what became known as underground comics. Published and distributed independently of the established comics industry, most of such comics reflected the youth counterculture and drug culture of the time. Many had an uninhibited, often irreverent style; their frank depictions of nudity, sex, profanity, and politics had no parallel outside their precursors, the pornographic and even more obscure "Tijuana bibles". Underground comics were almost never sold at news stands, but rather in such youth-oriented outlets as head shops and record stores, as well as by mail order. Frank Stack's The Adventures of Jesus, published under the name Foolbert Sturgeon, has been credited as the first underground comic. Alternative comics Main article: Alternative comics The rise of comic book specialty stores in the late 1970s created/paralleled a dedicated market for "independent" or "alternative comics" in the U.S.