When you find an image online, the best practice is to assume that its use is protected by copyright. Some creators (and more every day) are relaxing the protections provided by copyright and intentionally are releasing their work under open content licenses such as Creative Commons licenses.
This guide page collects some recommended collections and repositories for finding images that are designated for open or educational use. Most are released with Creative Commons licenses. For more information about understanding copyright and licensing, visit this page on our OER guide.