On this page there are sites for finding Public Domain and Creative Commons photos. Although Public Domain Images require no attribution, it is best practice to include a link to the photo and to attribute the photographer and the website where you found the photo (e.g., Photo by Jeremy Bishop on Unsplash) . Creative Commons Images have seven different licenses. You must pay attention to the license acronyms and cite accordingly. Below is a chart, found on Wikipedia, that describes what can and cannot be done with images that have the various licenses.