A chapter is a main thematic division within a writing of relative length, such as a book of prose, poetry, or law). A book with chapters may have multiple chapters that respectively comprise discrete topics or themes). Chapters can be numbered, titled, or both, and they give readers of long works a place to pause and provide a rhythm to the experience of reading. Chapters can be used to develop characters or relationships between characters, build a world or set a scene, or tell a shorter story that moves the larger story forward.
Chapters are present in books, documents, thesis papers, and other types of long-form literature. Non-fiction books, especially those used for reference, almost always have chapters for ease of navigation, and in these works, chapters are often subdivided into sections). Larger works with a lot of chapters often group them in several parts as the main subdivision of the book). The chapters of reference works are almost always listed in a table of contents). Novels sometimes use a table of contents, but not always). If chapters are used, they are normally numbered sequentially, and they may also have titles, and in a few cases, an epigraph or prefatory quotation).
The length of a chapter can vary greatly, and there are no set rules for how long a chapter should be. Short chapters are good for plot-centered novels with fast pacing and suspense, while long chapters are good for epic drama, for world-building with background, and for developing characters at a leisurely pace. As a general rule, if a chapter is under 1,000 words, it might not be a whole idea or chapter, and if a chapter is more than 10,000 words, it might really be a part, not a chapter.
