Nonfiction books are literary works that are based on facts and information about the real world. They are the broadest category of literature and can cover almost any topic, from wild animals to Vikings. Nonfiction books should be based on facts and conclusions of the authors research or expertise, as opposed to the creativity of the authors imagination. Nonfiction books can be created with the help of a range of structures or formats such as reference works, life writings, literary criticism, and more. Some common types of nonfiction include biography, business, cooking, health and fitness, pets, crafts, home decorating, languages, travel, home improvement, religion, art and music, history, self-help, true crime, science, and humor. Nonfiction novels are a loosely defined and flexible genre that depicts non-fictional elements, such as real historical figures and actual events, woven together with fictitious conversations and uses the storytelling techniques of fiction.