Links to a useful PDF booklet describing 'Open Educational Resources'. There's an accompanying course, but you don't have to take it. The booklet notes, "A resource accessible for free over the Internet does not always signify that it is not protected by a copyright nor forbidden for reuse and reproduction. In fact, most of the time, the content is protected by copyrights not allowing reproduction. Where else an OER is distributed, licensed and shared with the background willingness to enable the user to adapt and use the content freely. There fore, the model of distribution and the license is always clearly mentioned."