What is copyright?
According to the U.S. Copyright Office, copyright is: "a form of protection grounded in the U.S. Constitution and granted by law for original works of authorship fixed in a tangible medium of expression. Copyright covers both published and unpublished works." 
The three requirements for copyright:
What does copyright protect?
Under 17 USCS Section 102 the following is protected:
"In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work."
Who owns the copyright?
-Derived from the Copyright Clearance Center's 2006 Copyright Education Series Foundations Workbook
How long does copyright last?
The United States has had several copyright codes in its history, so depending on when a work was created, it may or may not be protected by copyright. Check out the American Library Association's Digital Copyright Slider to see if what you want to use is in the public domain or covered by copyright.
What happens when copyright expires?
When the term of copyright expires (or an individual forfeits their copyrights using a CC0 license or something similar, see the Creative Commons tab for more information), a work is said to enter into the public domain.
The public domain refers to works that are not copyright protected and can be used freely, without seeking permission. Works can pass into the public domain through various ways, so it is important to always check carefully to determine if a particular work is really in the public domain before assuming you may use it without permission.
Anyone may reproduce, redistribute, or adapt works in the public domain. Permission for use is no longer required.
Due to the Copyright Term Extension Act of 1998 (also known as the Sonny Bono Act), no copyrighted works will enter the public domain until 2019.
Copyright Term and the Public Domain in the United States
Cornell University Library's chart illustrates when works pass into the public domain
Digital slider to determine if and when works will pass into the public domain
What does the right of "first sale" mean?
The "first sale" doctrine says that a person who buys a legally produced copyrighted work may "sell or otherwise dispose" of the work as he or she sees fit, subject to some important exceptions (Section 109a). "First sale" gives you the right to loan a legally purchased book or CD to your friend. Historically libraries have heavily relied on the first sale doctrine to lend books and other items to their patrons.
The first sale clause was enacted during a time when most copyrighted works were produced in physical formats that made such works difficult to reproduce on a large scale. Many protected works including books are now produced digitally, however, copyright owners have lobbied Congress for new laws that some feel may undermine the "first sale" doctrine.
Additionally, many publishers (most notably music publishers) are now creating works to include technologies that interfere with the "first sale" doctrine. Software companies also attempt to circumvent the first sale doctrine by characterizing the consumer purchase as a license rather than a sale.
First sale issues are entangled with licensing and Digital Millennium Copyright Act issues. To learn more about The Digital Millennium Copyright Act please see the American Library Association's Introduction to the DMCA.
"Books" by Rocket000 is licensed under CC-BY
Copyright Law for Librarians and Educators by 
The following are two recommended resources for Butler faculty who want to know how their work is protected via copyright.
Library Hours
Study Rooms
My Library Account
Library Website
