A postface is the opposite of a preface, a brief article or explanatory information placed at the end of a book. Postfaces are quite often used in books so that the non-pertinent information will appear at the end of the literary work, and not confuse the reader.
A postface is a text added to the end of a book or written as a supplement or conclusion, usually to give a comment, an explanation or a warning. The postface can be written by the author of a document or by another person. The postface is separated from the main body of the book and is placed in the appendices pages, that is to say at the end of the document. The postface presents information that are not essential to the entire book, but which are considered relevant.
There are at least two authentic examples of postfaces in published works. One can be found in the 1954 book Dali's Mustache: A Photographic Interview, by Salvador Dalí and Philippe Halsman. While the main body of the work is a collaboration, each author gets a few words to himself, Dalí in the preface and Halsman in the postface. Another occurs in the philosopher Martin Heidegger's essay The Origin of the Work of Art and is further cited in Jacques Derrida's reading of it in The Truth in Painting (1987).