How do the different services in Oracle SOA relate to each other?

I'm am trying to figure out how the Oracle "Layered Architecture Model" works, an开发者_高级运维d I am very confused about what the business, data, and presentation do, and how they relate to each other. I have seen many diagrams showing how this should work, but some real world examples would be useful?

For example I am guessing that web applications are what Oracle calls "Composite applications" and that these web applications are built up of what Oracle calls "Presentation Services".

Let me try to answer to the best of my knowledge:

1. The OSB is BEA's ALSB overhauled. The main purpose of this is the job of ESB. It sits between your presentation layer and rest of the application. It defines the boundaries of your application, and supports mediation between various units.
2. Your components and various subsystems that contain business logic (think of different departments in an organization) are termed Composites. For instance, these composites could internally use BPELs to represent business logic, and use JCA for reaching out services (database, ejbs, etc.,) local to them.
3. These Composites, if need to reach out to services outside their jurisdiction (sorry, could not think of a better word,) they need to contact the OSB.
4. Any internal requirements for a service mediation is satisfied by a Mediator (unfortunately, this is OESB overhauled)

As you can see, this is sort of a pathetic attempt by Oracle to sell both their original ESB solution, along with the products they bought from BEA. Let me tell you, nothing stops you from wiring your internal services in OSB itself (probably the ultimate direction of Oracle)

I am sure you will be able to find out more after rereading, and working hands on. Request to please update your question with your findings.