A non-fiction book is a work of literature that is based on facts, real-life events, and real people. It aims to convey information about the real world, rather than being grounded in imagination. Non-fiction can cover almost any topic, from wild animals to Vikings. Non-fiction books can be instructional, explanatory, discussion-based, report-based (non-chronological), opinion-based (persuasive), and relating (chronological recounting). The main goal of non-fiction is to provide information based on facts and conclusions of the authors research or expertise, as opposed to the creativity of the authors imagination. Non-fiction is a fundamental approach to narrative (storytelling), and often refers specifically to prose writing – in contrast to narrative fiction, which is largely populated by imaginary characters and events. Examples of non-fiction works include academic papers, biographies, memoirs, journalism, and historical, scientific, technical, or economic writings.