Narrative nonfiction has many different names, such as creative nonfiction, literary journalism, and fact-based storytelling.
Anyways, Narrative nonfiction is an alternative to the traditional newspaper pyramid structure. With this type of nonfiction, you don't present the main point in the first paragraph (also called compelling narrative because it keeps the reader reading to find out what exactly happens, and the journey to the epiphany is half the point. Narrative nonfiction has joining good research with compelling, character-driven storytelling (reads like a novel).
Hope I helped! :D