Fan Fiction
Fan fiction (also spelled fanfiction and commonly abbreviated to fanfic or fic when used in a singular sense) is fiction written by people who enjoy a film, novel, television show or other media work, using the characters and situations developed in it and developing new plots in which to use these characters. Characters and props from more than one media work may also be incorporated into a single fanfiction (known as crossovers).
Some writers of essays about fan fiction (usually writers of fan fiction themselves) suggest that fan fiction is simply a new incarnation of amateur storytelling: amateur storytellers are still making up new stories about their favorite characters for "amateur," uncritical audiences, but now those characters are Draco Malfoy and Sailor Moon instead of Brer Rabbit and Hercules. They consider modern fan fiction to be similar to a garage band: not quite a contribution to professional literature or music (although certainly a reflection of it), but a creative, devoted method of enjoyment.
Types of Fanfiction (some)
Mary Sue- a new "flawless" character enters the story and goes on to upstage the established characters. Often the Mary Sue represents an idealized author character.
Self-Insert- A sub-genre of fiction in which an author pens himself or herself into the fiction as an author character. According to detractors, the author becomes a Mary Sue
Crossover- where characters of different media franchises interact.
Songfic- A songfic is a story, often a one-shot (a fanfic with only one chapter), where the lyrics to a song, or sometimes a poem, are included in the body of the writing, and in someway are connected to the story.
Het- classifies a story which has as its main focus a relationship ("ship") between two characters of different genders. Het varies from innocent romance to explicit erotica.
Slash- A "slash" story has as its main focus a relationship ("ship") between characters of the same gender.
Lemon and lime- Explicit sex stories, especially in anime fan fiction.
Real person fiction- is a type of fanfiction written about real people such as actors, politicians, athletes and musicians.
Original fanfiction- It is worth noting that there is no such thing as an "original fanfic". The term is a misnomer that is sometimes applied to completely original works published online. It is inaccurate, however, because the work is not intentionally based on any previously existing story and is therefore not fanfiction.