The Open Access movement has the potential to open the gates
of scholarly resources to everyone, regardless of means or
affiliation, but the definition of OA is not entirely clear, and
far from well-understood.
Stevan Harnad and Peter Suber have been trying to hammer out
a definition that includes all of the variations. OA can include
material that is "digital, online, and free of charge", and also
material that is "digital, online, free of charge, and free of
unnecessary copyright and licensing [...]