What is a derivative work?
As defined by the Copyright Act, a derivative work is any work based on one or more preexisting works. This includes translations, dramatizations, movie adaptations, abridgments, and any form of transformation or adaptation. Examples of a derivative work would include the film version Silence of the Lambs, adapting the book, an English translation of “Don Quixote” and a drawing based on a photograph.
If the author of the derivative work had the original work’s author’s permission to use the underlying work (or if the underlying work was in the public domain) then the derivative work can be copyrighted on its own. Any such copyright protection will only extend to the original and creative elements added by the derivative work’s author to the original work - however, the originality added by the derivative work’s author must be substantial enough such that the derivative work is a meaningful variation from the original.