Book chapters are the individual parts of a book. They are the specific "blocks" that make up the entire book. The chapters typically begin with a chapter heading, which is often numbered.
Each chapter is responsible for covering a unique part of the book’s content, with the chapters often being divided into various subsections to break up the content further. Each chapter usually closes with a conclusion which is usually a brief summarization of the content of the chapter.
The aim of book chapters is to create an ordered, cohesive structure to the book. This makes it easier for readers to digest the book’s content, by allowing them to complete each section in sequence before moving on to the next.
Finally, the structure of book chapters can also be used to create a sense of narrative structure, as the content of each chapter links the preceding and succeeding chapter to form a single story arc.