Literary genres are categories that classify written works based on their style, form, and content. Common genres include fiction, non-fiction, poetry, and drama. Each genre has its own conventions and characteristics, which help readers understand what to expect from a particular work. Within these main genres, there are sub-genres that further define the type of story or information presented. For example, fiction can be divided into science fiction, fantasy, and mystery, while non-fiction includes biographies, essays, and self-help. These classifications help readers find books that match their interests.