Privileges are normally created for each menu item (display, output, or action) for an access level. Every menu item should be in a privilege, but you can add more than one menu item to a privilege if they must never be assigned different permissions, such as menu items that point to the same form. This is the most granular level, and will be grouped into duties and roles later.
Since the privilege assigns the access level, we will usually have two--to provide view only, and to maintain (full) access rights.