What is open content?

Open content, coined by analogy with "open source" (though technically it is actually share-alike with no non commercial prohibition), describes any kind of creative work including articles, pictures, audio, and video that is published in a format that explicitly allows the copying of the information. Content can be either in the public domain or under a license like the GNU Free Documentation License. "Open content" is also sometimes used to describe content that can be modified by anyone; there is no closed group, like a commercial encyclopedia publisher, responsible for all the editing.

Reference:

1.http://en.wikipedia.org/wiki/Open_content