Differences between "Royalty-Free", "Public Domain", "Creative Commons" etc

Question

Is there a simple summary somewhere (or can someone provide one) of all the different kinds of legal terms for how and where we can re-use someone else's images?

For example these terms are bandied about and they all sound reasonably similar:
Royalty-Free
Creative Commons ^{(which seems to have a bunch of subcategories)}
Public Domain
... and others

These terms are easily to google but it's hard to work out where terms are simply synonyms for each other and where there are subtle differences.

For example, on Flickr the status of images are clearly labelled and you can click through for a definition (somewhat legalese) on CreativeCommons.org. But Google Images search (Advanced) has a filter which is deliberately "plain English":

So an overview, not too legal, would be great.

This is asked from the point-of-view of a web designer looking to browse and use other people's images in (commercial) websites, but correctly and fairly. Not an author looking at protecting my own copyright.

Answer 1

I think there are no situations where the terms are simply synonyms for each other. It is a complicated matter indeed.

Here are simplified definitions:

• Public Domain: no restrictions, no copyright claim (not possible in some countries).
• Creative Commons: work may be used but in compliance with the stated restrictions.
• Royalty Free: you buy a license once and can use the work according to the license.
  
  

For me, the options of Google image search are misleading. What is "free to use" supposed to mean? Probably free of charge. But you'd have to investigate each time anyway what the license is and what usage restrictions there are.

Here is my favorite license.

Answer 2

Adding to John's answer, which has all the important info about the three categories you mention.

You wonder about Creative Commons. They are a set of copyright licenses (not an alternative to copyright, they work alongside it). The 'advantage', so to say, is you can choose your copyright terms to best suit your needs.

Some of the most used CC licenses are:

Attribution

Lets others distribute, remix, tweak, and build upon your work, even commercially, as long as they credit you for the original creation.

Attribution-ShareAlike

Lets others remix, tweak, and build upon your work even for commercial purposes, as long as they credit you and license their new creations under the identical terms. This license is often compared to “copyleft” free and open source software licenses.

Attribution-NonCommercial

Lets others remix, tweak, and build upon your work non-commercially, and although their new works must also acknowledge you and be non-commercial, they don’t have to license their derivative works on the same terms.

Attribution-NoDerivs

Allows for redistribution, commercial and non-commercial, as long as it is passed along unchanged and in whole, with credit to you.

And then you have some combinations of the previous (like Attribution-NonCommercial-ShareAlike or Attribution-NonCommercial-NoDerivs). You can see the whole list here.

In your case, because you want to use images for commercial web, an Attribution license would be enough (as long as you mention the author somewhere in your project). The only materials you couldn’t use would be the NonCommercial ones.