"Public domain" is a term that refers to creative works that are not protected by copyright, trademark, or patent laws. As the name suggests, these works are owned by the public. Therefore, the exclusive rights that are typically granted to the owner of a copyrighted work are granted to the public. However, while anyone may use a work in the public domain without obtaining permission, no one can own public domain work.
How do works become public domain? There are four common ways:
For works published in the United States before 1923 the copyright is expired. More specifically, if the work was published in the U.S. before January 1, 1923, you can use it--in the U.S.--without permission. These rules and dates apply to all works, whether created by an individual author, a group of authors, or an employee (a work made for hire).
This is perhaps the simplest of the copyright expiration guidelines. There are, however, instances where works published before 1964 are in the public domain because the copyright was not renewed by the deadline then provided under the law.
For more detailed guidelines and explanation of copyright term and the public domain please consult the downloadable public domain chart or the digital copyright slider featured in the links on this page, as well as the links below:
Is a book published in 1925 without a copyright notice in the public domain? Is permission needed to use an unpublished work?
Use these following to get a better understanding of the dates and variables affecting copyright term and the public domain.
Sara Grozanick, Alyson Pope, Maureen Diana Sasso