Generally speaking, books with more than a thousand pages were large-scale literary works such as historical novels, science fiction novels, fantasy novels, and so on. In these novels, there were often many complicated plots and character relationships that required the author to spend a lot of time and energy to construct and describe. Therefore, these books usually contained a lot of details and content, and often had many pages. There are also some non-literary works such as scientific works, philosophical works, etc. They may also have many pages, but their main purpose is to convey ideas and opinions rather than to describe plots and characters. Therefore, the number of pages in these books did not necessarily represent their content.