Overview 
Basic, non-OBN navigation enables developers to provide links that contain a navigation node name. When a user clicks the link, the iView, page, workset or role corresponding to the navigation node is displayed.
OBN enables a developer to provide navigation links whose navigation target is resolved at runtime.
With OBN, developers provide links that contain a business object name and the name of one of its operation. When the user clicks the link, the navigation target is resolved dynamically, based on the following criteria:
The navigation targets assigned by the administrator to the operation.
The priority of each navigation target assigned by the administrator to the operation
The roles assigned to the current user.
The administrator can assign many navigation targets to an operation, but the user can only navigate to navigation targets in the user's assigned roles.
Business Objects and Operations
Business objects and operations are PCD semantic objects whose attribute values are used to tag portal content (iViews and pages).
When a request is made to navigate to a specific business object and operation, OBN searches the PCD for content tagged with the specified business object and operations, and then uses additional logic to choose from this content to which iView to navigate.
For more information, see OBN Terminology.
OBN Benefits
The following are the key benefits of OBN:
A developer can specify navigation to an iView without the need to know its location in the PCD. In fact, a navigation link can be created to another iView before that iView is created.
For the same link, different user interfaces can be provided to different users based on each user's role.
For a link that specifies Customer as the business object and Details as the operation, a sales person could receive an iView that displays contact information while a sales manager could receive an iView that displays customer order information.