Copyright laws protect the rights of creators. It gives them exclusive right to their creations, so that no one else can profit from them without the copyright holder's permission. While copyright does restrict the ways the people can use works created by others, it is thanks to copyright that we have creative works to learn form and enjoy in the first place. Without it, creators would have no guarantee of what would happen to or who would profit from their creations, so they may not create them in the first place. What a sad world this would be without copyright!
Read the Copyright Law of the United States
"Understanding Copyright" by Renee Hobbs, Katie Donnelly and Sandra Braman