A comic book -- or comic for short -- is a magazine or book containing sequential art. Although the term implies otherwise, the subject matter in comic books is not necessarily humorous; in fact, it is often serious an action-oriented. Comic books are so called because some of the earliest comic books were simply collections of comic strips (most of which were humorous) that had originally been printed in newspapers. 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.