A lot of people think that all images on the web are free for anyone to use. The aim of this guide is to separate the wheat from the chaff – describe the difference between images that are absolutely free (public domain), “royalty free” and “rights protected”. 

Public Domain vs Rights protected vs Royalty Free:
Public Domain images are free for any sort of use. Wikipedia has a great article on them available on their site so I'm going to try not to duplicate their useful content (which includes a list of sources for public domain images). What I will say is that according to copyright laws, any photographs taken on assignment working for the United States government or any photographs available for download on US government sites are automatically public domain.

Right Protected images are bought with a specific time limit for how long the image can be used for and with a specific project in mind (e.g. Use of an image on billboards in Berlin, Germany for 5 weeks). The time period and specific use are negotiated beforehand with either the photographer or a middleman. For an additional fee others will not be able to use the same image during the time period. This is useful for big businesses who want to advertise effectively.

Royalty free images are bought for a once-off fee. They can be used in as many ways as the buyer wants. Others can also use the same image if they too purchase it. Higher resolution images (used for print publications or posters as opposed to on websites) usually cost more.

Action Steps
The best contacts and resources to help you get it done

Tips & Tactics
Helpful advice for making the most of this Guide

• For Web Designers - you can usually right click on an image and click "save as..." to use it in your layout (you may get a watermark).
• Make sure you get images at high resolutions - especially if using for print.
• High quality images are hard to come by in the Public Domain and free sector. You will probably have to pay to get that killer design.
• Use assignment photography if you know the kind of shots you want. If you don't know, browse online stock photography stores.