Fan Fiction (or fanfic as it is sometimes called) is fiction written by fans of a particular television series or movie for other fans of the same series or movie. No infringement on the original copyright of the production is intended. Many times this fiction is written to fill in gaps or extend scenes from what is broadcast. The most well known fanfic was written by fans of Star Trek. It has since spread to many of today's television shows.
I have written fanfic based on four shows (so far <g>), Beauty and the Beast, Early Edition, Lois and Clark: The New Adventures of Superman and Stargate SG1. One story has been published in a Beauty and the Beast convention fanzine. Other stories include, "The Cat In The Hat Comes Back", published as part of Lois and Clark's Season Five,"Mover's and Shakers" published as part of Lois and Clark's Season Six and parts four and twenty-two of the first Early Edition round robin, "Exposed".