Story structure
Epistolary novel
A novel told through fictional documents, classically letters between the characters, and in modern practice diaries, emails and blog posts.
An epistolary novel is "a novel written as a series of letters between the fictional characters of a narrative." The name comes from the Greek epistolē, "letter," through Latin and "epistle," and the label has widened to any novel told through fictional documents: diaries, newspaper clippings and, lately, emails and blog posts. Richardson's Pamela and Clarissa fixed the form, Les Liaisons dangereuses and The Sorrows of Young Werther carried it across Europe, and Frankenstein, Dracula, The Color Purple and We Need to Talk About Kevin show its modern range.
The form pays two ways. Realism: the documents exist inside the story, so no outside narrator vouches for them, and multiple correspondents give multiple viewpoints without an omniscient narrator. Constriction: the reader knows only what the writers put on the page, and the gap between what different correspondents know, the article's "discrepant awareness," is pure suspense. That discipline is limited point of view enforced by the form itself, and the fictional editor presenting the papers is a frame story in miniature.