Distributed objects are decentralized objects stored on the address space of several systems, which cooperate with the objects on the different systems. The intermediary role necessary for cooperation is performed by the Object Request Broker (ORB).
Object Request Brokers allow objects that are distributed across many computers to collaborate efficiently and are represented as if they are in the same address space. The ORB has a list of all accessible components and passes tasks to the correct agent.
ORB has been standardized by the Object Management Group( OMG) under Common Object Request Broker Architecture( CORBA) and performs the intermediary function by accepting requests to objects, locating the objects, and transmitting the request and result. Clients and servers can be connected and communicate with the same ORB or with different ORBs using inter-ORB communication.
Possible ORB implementations are specified in different implementation classes: Client- and implementation-resident ORB, Server-based ORB, System-based ORB, and Library-based ORB. Well-known object request brokers (ORB) include Common Object Request Broker Architecture (CORBA), Distributed Component Object Model( DCOM), and . NET.