The "all rights reserved" default of copyright requires those seeking to reuse content to seek permissions directly from copyright holders, which is not always a straightforward process. To make this process easier Creative Commons licenses give creators the flexibility to define the terms under which their content can be reused by others using a system of publicly available licenses with standard legal terms.
If you are an author, artist, or other creator, publishing your work under a Creative Commons (CC) license makes it easy to share with others under terms that you choose. Many Open Educational Resources, which are designed to be shared with an adapted by educators, are published under CC licenses because the licenses are easy to understand, standardized, and designed for online use.
"C - Clones or Creative Commons" by Kristina Alexanderson is licensed under CC BY-NC-ND 2.0.
Content published under a Creative Commons license can be reused under the conditions of the license, but must be attributed appropriately. Read more about how to do this at the Creative Commons Wiki: Best Practices for Attribution.