Book length refers to the number of words, pages, or chapters in a book. It can vary widely depending on the genre and target audience. For example, a typical novel may range from 70,000 to 100,000 words, while children's books often have fewer than 1,000 words. Publishers often categorize books based on their length, such as novels, novellas, and short stories. Understanding book length is important for authors and readers alike, as it can influence the reading experience and the time commitment required to finish a book.