Copyright - Copyright is a form of protection provided by the laws of the United States (title 17, U. S. Code) to the authors of “original works of authorship,” including literary, dramatic, musical, artistic, and certain other intellectual works. see http://www.copyright.gov/circs/circ01.pdf
Intellectual Property - a work or invention that is the result of creativity, such as a manuscript or a design, to which one has rights and for which one may apply for a patent, copyright, trademark, etc. see World Intellectual Property Organization
Public Domain - a public domain work is a creative work that is not protected by copyright and which may be freely used by everyone. The reasons that the work is not protected include:
(1) the term of copyright for the work has expired; (2) the author failed to satisfy statutory formalities to perfect the copyright or (3) the work is a work of the U.S. Government
Royalty Free (RF) does not mean free. Don’t let it mislead you. RF means that after the initial permission is secured, usually through a payment of some kind, additional uses can be made without payment. RF is multiple use free of royalties. Pay once, use the photo in a book, upload it to your website, print out some fliers. You still had pay for it at the outset.
Conversely, if you are looking for free pictures and stumble on a site with images offered “Royalty Free”, RF does not mean you can take them!
Rights-Managed (RM) use, is where the creator and the user reach a more tightly controlled agreement regarding multiple uses. For example, a RM image appearing in the first edition of a textbook might need to be re-licensed for a fee in order to be cleared to appear in the second edition. RM is the traditional way for licensing intellectual property, and remains in use partly because the details of an explicit license contract lessens risk and makes legal departments happy.
In general, the author or creator of a work initially owns its copyright.
There are exceptions to this rule. If a work is created by an employee in the course of his or her employment, the employer usually owns the copyright. Similarly, "work for hire" done by contractors is usually owned by the commissioning person or organization.
Copyright holders may voluntarily release some or all of their rights.
For example, some academic, scholarly or not-for-profit organizations make content freely available under a range of Creative Commons licenses. Open access journals, in particular, often use Creative Commons licenses.
Copyright holders often sell or transfer some or all of their rights to a distributor or a publisher.
It is common for publishers to ask you to transfer to your copyrights to them as a condition of publication.