"... What Exactly Is A Free Image?
When we talk about free images, there are three terms which you will encounter in your search.
Royalty free images:
These images are not free. You have to purchase these images for a fee, but beyond that you can continue to use the image as long as you want. But this is a non-exclusive right as others may also purchase the same image for use.
Public Domain images:
Images which are not covered by any copyright and are available free of charge are called public domain images. Images whose copyright have expired also fall under the public domain. To put it this way, any image which is freely available may not be a public domain image; but a public domain image is freely available for use without permission.
Creative Commons images (or the licenses) should not be confused with public domain and free-to-use images. Creative Commons is a set of free licenses which cover fair use and allow creators to reserve some rights for themselves while freeing up the work for the benefit of the public. Learn more about Creative Commons on the CC website.
Our search for free images shall cover the last two types – public domain images and images licensed with CC...
Via André Manssen