Over the years, the term has come to be used more broadly, describing both expository and narrative nonfiction that makes use of elements originally considered as exclusive to fictional texts. And as result, most of the trade nonfiction titles currently published for children include a mix of these creative elements.
Biographies and history books generally feature a narrative writing style and include central characters, real dialog, and scene building. Science books often feature an expository writing style and employ strong voice, point of view, innovative structure, and carefully-crafted literary language that delights as well as informs.
Never, never, never does creative nonfiction refer to books that take creative liberties with the truth. Everything must be accurate and verified through fastidious research. Any kind of undocumented embellishment kicks a piece of writing out of the nonfiction realm.