The term series may refer to:
- Category Romance which is one of the Romance Genres consisting of books that are not necessarily related by a common topic or story. These books are called "series" because they are issued with numbers identifying the order of their publication. Numbered series may be found in category:Numbered Series.
- Romance Series (category: Romance Series) is a general description of related books which may be published by a Category Romance publisher or by any romance publisher, written by the same author or more than one author.
- Publisher Promotion Series (category:Publisher Promotion Series) is a category of a group of books put together by publishers based on a promotion concept, in which the books are not otherwise related and there is no continuity between the books. These can be called series or "flash" based on the flash or logo on the cover of the books identifying them as related. For example, the publisher Phaze promoted a limited number of books on the topic of summer in the flash Sparkler.
- Publisher Continuity Series (category:Publisher Continuity Series) is a specific category of related books put together by publishers into a series that fit into a concept, or tell a continuing story over several books by different authors. These can also be called continuity or series.
- Romantic Series (category: Romantic Series) is a specific category of books which contain an overall plot that is not resolved until the series is ended.
- Series is a page with a list of related books by the same author which are based on a family or built around an institutional structure. Another place to find related books by the same author is in the category:Authors' Series.