Copyrighted photos-the legal right of creative artists or publishers to control the use and reproduction of their original works
Stock Photos-are professional photographs of common places, landmarks, nature, events or people that are bought and sold on a royalty-free basis and can be used and reused for commercial design purposes. The photographer (or stock photography distributor) has ownership to the images, and the commercial designer has some limited usage of the photo (which is set out in the Terms of Service by the company you purchase the stock photos from). Some conditions of use may include things such as use of the images is licensed, not sold or in case of a stock photo being used in a magazine there may be a maximum number of copies of the image allowed to be printed under the agreement.
Public domain photos-Public domain is clip art, images, text, programs, etc. that is not copyrighted. Public domain clip art has no terms of usage or conditions attached and you may copy it, sell it, claim it as your own and use it in any manner that you wish. Public domain is often used incorrectly on Web sites when describing freeware, shareware, linkware and Web collections of clip art.
Royalty free photos-Clip art, images, graphics, photographs, art, music and other created content which may be offered to the public or individuals (normally for a specified amount of money) to be used in specified ways (terms of usage). The creator retains all copyrights and publishing rights. You may use and publish the clip art, images, music per the specified terms of usage but may not sale or distributed to a 3rd party.