(written from a Production point of view)
The Official Star Trek Fact Files was a by Paramount Pictures licensed series of part-work magazines distributed in the UK, Europe and Australia by GE Fabbri, and was designed to give information about the Star Trek universe, written from an in-universe point of view. It ran from 1997 to 2002, with 304 issues of 24 pages each, totaling a work of 7296 pages of in-universe information.
In 2003, a translated version of the Fact Files was released in Japan, which, while much the same as the English language version, rearranged some parts and added some information, mostly to do with Star Trek: Enterprise and Star Trek Nemesis, resulting in a ten issue longer run of the Japanese version.  Between 1999 and 2004, a German language edition was also released under the title Die Offiziellen Star Trek Fakten und Infos as well as a French one, Star Trek Les Dossiers Officiels (published by Data Base Factory). The French edition came with one-episode VHS tapes of Star Trek: The Next Generation and unlike the German edition, did not complete the whole run of 304 issues, but ceased publication after 117 issues, making room for the newly conceived Star Trek: Les Nouveaux Dossiers Officiels. Likewise an Italian language edition, Star Trek Official Files, published by De Agostini was published but not completed, ceasing publication after 120 issues.
The series covered all seasons of Star Trek: The Original Series, Star Trek: The Next Generation, Star Trek: Deep Space Nine, Star Trek: Voyager and the first season of Star Trek: Enterprise, as well as the first nine films. Although based on canon productions, and featuring graphics and information directly taken from the studio, Fact Files often introduced non-canon speculation in its reference material. It did not incorporate any information from Star Trek: The Animated Series, for at the time of publishing TAS was not considered canon. For all language editions applied that each magazine consisted of a number of articles, to be taken apart and filed under their respective sections, they in turn to be collected in several binders (one binder being supplied every 16 issues).
The Fact Files received some criticism in fan circles for inaccuracies, notably in the starship sections. However, as Larry Nemecek, a major contributor, explains in the talk section of the Akira class: "[...] in their defense, the Brits *were* promised all this tech and source detail they were used to with [their] other techie partworks, and then left hanging when it didn't exist--no excuse, but that's what happened. I did some tech writing, but mainly I tracked source refs, imagery and art materials in both the uncharted Licensing archives (some buried, that the dept. didn't even know existed) or from chased-down personal sources." (source) For this reason Fabbri employed an art department to supplement art and graphics where official source material was lacking.
An officially licensed publication, Paramount Pictures assigned three Star Trek staff members to assist Fabbri's editorial office in researching and collecting reference material for use in the publication, Penny L. Juday (credited as Penny Smartt-Juday) as research coordinator, Larry Nemececk as photo editor and author and from issue 71 onward Guy Vardaman as art director. Other Star Trek affiliated people who at certain times contributed were Tim Gaskill as consultant editor as well as Judith and Garfield Reeves-Stevens as authors.
As a parts work, each (double-sided) sheet was endowed with a designation, to wit, a "file"-number with a corresponding sub-ordinated "card"-number.
Section 1: A Guide to the Star Trek Galaxy
- This section featured a timeline of canon events, and file sheets on various planets, spatial phenomena and historical artifacts encountered by the crew of each show. It also featured specialized sections on the Federation, the Vulcans, the Klingons, the Romulans, the Cardassians, the Ferengi, the Dominion, the Borg and the Q Continuum. The final "file" in this section dealt with less influential and one-time-only aliens such as the Vidiians and the Mintakans.
Section 2: Federation Starfleet
- Covered various aspects of Starfleet, with specialized files on each canon USS Enterprise, Deep Space 9, the USS Voyager, the USS Defiant, Enterprise NX-01, various runabouts and shuttle seen in each series, and one-time-only ships and space stations such as the USS Melbourne, the USS Relativity and Deep Space Station K-7.
Section 3: Non-Federation Starships
- Featured files on non-Starfleet vessels from Federation races, such as the Phoenix and the Xhosa; Klingon starships, Romulan starships, Cardassian starships, Ferengi starships, Borg starships, Dominion starships, Maquis starships, and a file on various starships and bases belonging to the various other races seen on Star Trek, from Kazon ships to the Fesarius to the Caretaker's array.
Section 4: Personnel Files
- Featured files various characters seen on Star Trek, from James T. Kirk to Weyoun to Jetrel. It had a special file for Starfleet personnel, with special attention played to the main characters of each series, non-Starfleet Human characters, and a file each for Klingons, Romulans, Cardassians, Ferengi, Borg, Changelings, Androids, omnipotent beings (primarily various Q), Vulcans and a file for "guest" characters.
Section 5: Equipment and Technology
- Dealt with transporters, weapons, communication, Starfleet uniforms and other various pieces of technology seen on the series.
Section 6: Starship Log
- Contained a file for each Star Trek series (ENT seasons 2-4 are not covered) and every film up to Star Trek: Insurrection. Within each file was a sheet for each episode with a synopsis, stills, quotes (usually the Captain's Log from that episode), and trivia.
Section 7: Database
- Served as an index for the entire magazine series.