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Fan fiction (also fanfic; from English fan - fan and fiction - fiction) is a type of fan creativity for popular works of art (so-called fan art in the broad sense of the word), a derivative literary work based on some original work (usually literary or cinematic), using its plot ideas and/or characters. Fan fiction can be a continuation, a prequel, a parody, an "alternate universe," a crossover ("interweaving" of several works), and so on.

Another definition: fan fiction is a genre of mass literature created by a fan of an artistic work, not pursuing commercial goals, for reading by other fans.