Copyrights are used primarily to protect the expression of ideas. As long as the expression of those ideas are fixed in a tangible medium and have at least some creative element in them, they can be protected.
Some of these mediums include art, photography, choreography, movies, music, writings, and software. Note that the important distinction between patents and copyrights is that while patents protect the underying ideas of an invention, copyright law only protects the EXPRESSION of those ideas. An idea which is expressed in a different manner than the original will not be susceptible to a claim for copyright infringement.