Much of what we have learned about clients and servers may be considered to be core ORB services. Starting from the core ORB We may take a building block or component view 1) Stub. So that the Stubs and the Dll are simply client focused services offered by the ORB. The Object Adapter and Skeletons are server-focused services.
There is also server-focused counterpart to the DLL; called the Dynamic Skeleton Interface (DSI), that allows Servers to implement an interface for which there is no compile-time knowledge. All of the services may be used interchangeably when sending CORBA requests or receiving CORBA replies There are some services that the specification says must be provided directly by the ORB, such as initialization of CORBA Object Reference Conversions, via an ORB interface. From this statement, it is easy to see that the ORB offers a rich set of services to CORBA clients and servers alike.