While you will be able to find a huge amount of visual content that is available within Public Domain, there is another option called Creative Commons that you should be aware of. Unlike Public Domain, where content belongs to all mankind. The content within Creative Commons still belongs to the person who created it. For pictures such as camera photographs, any content classified as Creative Commons would still belong to the photographer or the entity that commissioned the photographer.
To learn more, click the link below.
Tutorial Code: 09 11 04
Previous: 09 11 03 Attributing Creative Commons Pictures in PowerPoint Slides
Next: 09 11 05 Google’s Image Source Search