Copyright protects original creative works including books, movies, pictures, choreography and songs. It does not protect ideas, facts or data. Under copyright law, only the copyright holder can reproduce, display or share the work. Fair use allows limited use of copyrighted material for purposes like teaching or commentary. To determine fair use, one considers the purpose, nature, amount and commercial effect of the borrowed material. Plagiarism involves passing off someone else's work as your own and can have serious academic consequences, so it is important to properly cite sources.