Copyright is a type of legal protection provided to the authors of creative works. (Copyright Basics)
The US Copyright Act lists six rights exclusive to the copyright holder:
Authors are not required to register their works or use the © symbol in order to hold their exclusive rights. In addition, authors can agree to transfer these rights to someone else, such as a publisher, who will sell copies of the work. (Copyright & Fair Use, Stanford University Libraries) They may also license all or a portion of their rights for various lengths of times and to various people or entities.
In the United States, copyright law has its foundation in the US Constitution. Article 1, Section 8 states:
The Congress shall have the power to [...] promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writing and discoveries.
The 1976 Copyright Act (17 U.S.C. § 101 et seq.) established copyright law in the US as we know it today. From 1976 to October 2007, there have been fifty-nine amendments to the law. (U.S. Copyright Office: Copyright Law)
Except as allowed by law, it is a violation of [UNC Copyright Policy] and law for University faculty, staff, or students to reproduce, distribute, display publicly, perform, digitally transmit (in the case of sound recordings), or prepare derivative works based upon a copyrighted work without permission of the copyright owner.
Copyright law covers "original works of authorship fixed in any tangible medium of expression from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device" (Copyright Act, 17 U.S.C. § 102).
Types of original works include literature, music, drama, computer programs, visual art, and many other forms of expression.
Copyright protection does not extend to ideas, facts, or procedures.
By their definition in the U.S. Constitution, copyright terms are limited. How long a work's copyright term lasts depends on when the work was published. Here are some general rules for textual works published in the U.S.
For more detail, see Copyright Term and the Public Domain in the United States.
Copyright also does not cover works in the public domain. These include:
Works in the public domain can be used freely.
The following works are all protected by copyright law:
However, the following works are not protected by copyright law: