Series
A book series is a sequence of books having certain characteristics in common that are formally identified together as a group. Book series can be organized in different ways, such as written by the same author, or marketed as a group by their publisher.
Some works in a series can stand alone—they can be read in any order, as each book makes few, if any, reference to past events, and the characters seldom, if ever, change. Many of these series books may be published in a numbered series.