What is the public domain? Why does it matter to you? The public domain is not a place. It’s a concept that refers to everything not protected by copyright in the United States. It includes works that were never protected by copyright as well as those whose term of protection has expired. If it’s in the public domain, it’s free to use. The existence of the public domain means that there is an extensive and growing cultural legacy, which is available to everyone as a resource for study, development, and material for new creative works. Let’s explore how works become a part of the public domain. First, material that is not covered by copyright is in the public domain from the time it is created. For example, facts and ideas are not protected by copyright law and are therefore in the public domain. But note that some things that are not protected by copyright could be covered by other legal protections, such as patent or trademark laws. Second, a work can enter the public domain if it was protected by copyright law, and the amount of time it was protected for has expired. Under the Constitution, copyright protection has a limited time. The founding fathers gave Congress "the power to promote the Progress of Science by securing for a limited time to authors the exclusive right to writings." Copyright law has changed over time, so when and how a work expires changed, too. Under current law, copyright protection covers an original and creative work as soon as it is fixed in a tangible medium, even if the owner has not registered the copyright. The term of copyright protection is the length of time that a work is protected. The term has changed several times over the years. The copyright office has a number of resources that discuss copyright terms and requirements, including our circulars. These resources can help you determine if a work is in the Public Domain. You can research copyright records on-site and at copyright.gov. But, you do have to be careful before using material you think is in the Public Domain. The basis for a work could be material that is in the public domain, but someone else could have made new contributions to that material that may be protected by copyright. Take Romeo and Juliet. Shakespeare’s original play is in the public domain. There are lots of movies, books, and updated plays that people have created based on Shakespeare’s original work to which they have added their own original elements that are copyright-protected. The new creative expression in these works may be protected by copyright. So, when seeking inspiration from a work in the public domain, go back to the original source. Materials in the public domain can be found all over. Libraries, museums, and archives are great resources. For more information about the public domain and the U.S. Copyright Office, visit copyright.gov.