A knol is one unit of knowledge. The term was popularized by Google, with their now discontinued Knol project.
At ArchOpus wiki, we have one free section, and this Knol section, of which this is the main page. The Knol Section is available only for those students who have enrolled here. Currently, all students would get this free but at some point, the Knol section would only be available for those students with paid accounts.
All mentors would have access to this Knol section – for they would be the one putting up and editing content here.