A comic book is a magazine or book containing sequential art in the form of a narrative. Comic books are often called comics for short. Although the term implies otherwise, the subject matter in comic books is not necessarily humorous, and in fact its dramatic seriousness varies widely. The term "comics" in this context does not refer to comic strips (such as Peanuts or Dilbert). In the last quarter of the twentieth century, greater acceptance of the comics form among the general reading populace coincided with a greater usage of the term graphic novel, often meant to differentiate a book of comics with a spine from its saddle-stitched form, but the difference between the terms is ambiguous, as comics have become increasingly available in libraries and mainstream book stores.
Some of the earliest comic books were simply collections of comic strips that had originally been printed in newspapers, and the commercial success of these collections led to work being created specifically for the comic book form, which fostered specific conventions such as splash pages. Long-form comic books, generally with hardcover or trade-paper binding came to be known as graphic novels, but as noted above, the term's definition is vague. Like jazz music (and a handful of other cultural artifacts), comic books are a rare example of an indigenous American art form, though prototypical examples of the form exist.
American comic books have become closely associated with the superhero tradition. In the United Kingdom, the term comic book is used to refer to American comic books by their readers and collectors, while the general populace would likely consider a comic book a hardcover book collecting comics stories. The analogous term in the UK is a comic, short for comic paper or comic magazine.