Why The Rules Are In Place
Copyright laws were created to protect the creative works of individuals. These laws especially come up in the entertainment industry, because no one wants someone else to make money off of his work. Copyright laws protect works whether they are published or not.
Who The Rules Protect
Copyright rules protect anyone who creates something tangible. The rules protect anything from music and poetry to computer software. A big reason these rules are important, is that without such protection, people would have little incentive to create new music, write books, paint portraits, etc.
What Are The Consequences?
If the originator of the work decides to sue you for copyright infringement, you can face hefty fines. The amount would depend on how popular the original work was, if you made money off of the copyrighted material, and if the violation was intentional.
How to Copyright Something
Your work is copyrighted the moment you create it. However, there are ways to make the copyright more sustainable. One way is to register your work. You can do this by submitting an application, fee and copy of the work to be registered to the copyright office.
You are allowed to use portions of copyrighted works for certain purposes, such as in an academic setting, for reviews of movies or for news reporting.