(noun) - A catalogue raisonné is a book -- an exhaustive book -- that covers every known work of an individual artist up to the year of the book's publication. Joe Schmoe can't be the author, either. Typically, a catalogue raisonné is only written by the leading expert(s) on said artist, over the course of many years' research.
Within the covers, the author details each piece's (1) provenance, (2) size, (3) current condition and external sources in which the piece has been written up. Photographs and/or scans are a heavily prominent feature.
A standard catalogue raisonné also includes examples of the artist's signature (they all evolve, over the years) and/or marks, a brief biographical piece and information on works that are attributed to (but not authenticated to be of) the artist.
In short, if you are researching an artist's works, or have one of those delicious mystery pieces, the appropriate catalogue raisonné is your best bet for credible information.