Open Educational Resources are learning and teaching materials freely available for anyone (students or teachers) to use. Some Open Educational Resources (OER's) may have Creative Commons licenses limiting the type of usage. Interested in learning more about OER?
They make the world the classroom.
Some nice definitions:
"Open Educational Resources (OERs) are any type of educational materials that are in the public domain or introduced with an open license. The nature of these open materials means that anyone can legally and freely copy, use, adapt and re-share them. OERs range from textbooks to curricula, syllabi, lecture notes, assignments, tests, projects, audio, video and animation." (UNESCO). -- from UNESCO: What are Open Educational Resources?
"Open Educational Resources (OER) are high-quality, openly licensed, online educational materials that offer an extraordinary opportunity for people everywhere to share, use, and reuse knowledge. They also demonstrate great potential as a mechanism for instructional innovation as networks of teachers and learners share best practices." -- from William and Flora Hewlett Foundation
"Put simply, the fewer copyright restrictions are placed on the user of a piece of content, the more open the content is...Content is open to the extent that its license allows users to engage in the 4R activities. Content is less open to the extent that its license places restrictions (e.g., forbidding derivatives or prohibiting commercial use) or requirements (e.g., mandating that derivatives adopt a certain license or demanding attribution to the original author) on a user's ability to engage in the 4R activities." -- from Defining the "open" in Open Content