Periodical literature (also called a periodical publication or simply a periodical) is a category of serial publications that appear in a new edition on a regular schedule. The most familiar example is the magazine, typically published weekly, monthly, or quarterly. Newspapers, often published daily or weekly, are, strictly speaking, a separate category of serial. Other examples of periodicals are newsletters, literary magazines (literary journals), academic journals (including scientific journals), science magazines, yearbooks and comic books.