Public domain refers to creative materials that are not protected by copyright, either because their copyright term has lapsed or because they were never subject to copyright in the first place.
Although public domain is an important topic to consider in order to understand copyright law, it is not actually a part of copyright law! Rather, anything that is not covered in copyright law can be considered to be part of the public domain.
Everyday year on January 1, works that had previously been protected by copyright enter the public domain, leading to some to refer to January 1 as "Public Domain Day!"
Image credit: "happy public domain" by Laurel L. Russwurm is marked with CC0 1.0.
How do I determine if something is in the public domain? Copyright lasts for the lifetime of the creator plus 70 years, but sometimes it isn’t that easy! Copyright law has changed numerous times over the last 100 years, and terms can be different depending upon factors such as the year the material was created, the year it was published, whether the creator registered with the copyright office, the format of the material in question, and more.
Here are some tools for understanding the copyright status of creative material:
