The term Open Access describes the nature of access, rather than a specific business model, licence or type of content.
The primary difference between traditional publishing and open access is that in the OA model the bills are not paid by readers and do not function as access barriers. For more information see Why open access?.
This guide will help you:
The following video 'Open Access Explained!' was created by Piled Higher and Deeper (PHD Comics)
The benefits of Open Access and a list of principles under which the University operates with regards to OA.