Editorial Use: Permission to use in blogs, newspapers, magazines and other publications.
Commercial Use: Permission to use in marketing and advertising to promote a product or service.
Retail Use: Permission to use in the creation of a physical product to be sold. This includes prints, posters, and products that feature the photo (pillows, mugs, etc.). Sometimes talked about in the same context as commercial use, but it should be considered separately.
Exclusive and Non-Exclusive: Exclusive use means that the one who purchases the license from you is the only one who can use the photo. Non-exclusive photo licenses can be purchased and used by anyone and usually cost less.
Public Domain: Holds no restrictions or copyright claim and can be used for commercial, editorial, and personal purposes. Works created by U.S federal government agencies (such as NASA) generally fall into this category unless otherwise sated.
Creative Commons: Conditional usage of your work is allowed as long as it is in compliance with the stated restrictions. Attribution to credit the creator is sometimes required. Visit Creative Commons to generate a badge for this license for free.
Royalty-Free: Others can buy a license and use the photo for an unlimited duration and unlimited number of times. This is the most common type of license purchased and on the cheaper end of the spectrum since these photos are usually non-exclusive.
Rights-Managed: A one-time license can be purchased to use the photo with restrictions regarding distribution. Additional licenses must be purchases for additional use.
Right of Publicity: The subjects in your photos are entitled to certain rights when it comes to their inclusion in your photography, especially when it comes to commercial use. This is a separate concern from the copyright considerations above and you should seek a subject’s explicit permission first in order to be safe.