A Creative Commons license is one of several public copyright licenses that enable the free distribution of an otherwise copyrighted work. A Creative Commons license is used when an someone wants to give people the right to share, use, and/or build upon a work that they have created. It provides a person flexibility and protects the people who use or redistribute an author’s work from concerns of copyright infringement as long as they abide by the conditions that are specified in the license by which the author distributes the work. The most open license, and the license generally recommended for open educational resources, or OER, is Creative Commons Attribution (CC BY). CC BY means that anyone may distribute, remix, tweak, and build upon the creator’s work, even commercially, as long as they give credit. All Creative commons licenses require attribution; on top of attribution, the creator may choose to add a combination of three other conditions, which result in the rest of the licenses you see here. For example, if creators want to prohibit commercial uses, they would add the NonCommercial condition; if they want to require that downstream users also reshare their adaptation under the same terms, they would add the ShareAlike condition; if they want the work to be redistributed unchanged, they would add the NoDerivatives condition. More than half a billion Creative commons licensed works exist on the Web free for teachers and students to use, build upon, and share. Many of these works are educational resources that have been licensed by teachers, educational organizations, schools, and even the government. You can find Creative commons licensed content by starting with the CC search tool, which isn’t a search engine but rather a portal to third party owned search services that have added Creative commons license filters. Creative commons licenses are the legal tools that help you discover, share, remix, and build upon educational resources, which is what makes them open educational resources, or OER. In a sense, Creative commons licenses are the infrastructure of roads underlying the ecosystem of OER to make reuse and sharing possible. As long as the roads are properly maintained — that is, the Creative commons licenses/legal tools are kept up to date — creators have more options for how to share their works, educators have easier means of discovering and sharing OER, and students are empowered to build on what came before.