Fan fiction
Fan fiction or fanfiction, also known as fan fic, fanfic, fic or FF, is fiction typically written in an amateur capacity by fans as a form of fan labor, unauthorized by, but based on, an existing work of fiction. The author uses copyrighted characters, settings, or other intellectual properties from the original creator(s) as a basis for their writing and can retain the original characters and settings, change them, (by either adding or removing characters, themes, plot points, etc ) or both.