From The Art and Popular Culture Encyclopedia
A periodical literature (also called a periodical publication or simply a periodical) is a published work that appears in a new edition on a regular schedule. The most familiar example is a newspaper, but a magazine or a journal are also examples of periodicals. These publications cover a wide variety of topics, from academic, technical, trade, and general interest to leisure and entertainment.
Articles within a periodical are usually organized around a single main subject or theme and include a title, date of publication, author(s), and brief summary of the article. A periodical typically contains an editorial section that comments on subjects of interest to its readers. Other common features are reviews of recently published books and films, columns that express the author's opinions about various topics, and advertisements.
A periodical is a serial publication. A book series is also a serial publication, but is not typically called a periodical. An encyclopedia or dictionary is also a book, and might be called a serial publication if it is published in many different editions over time.