ISO/IEC 19500-1:2012 specifies the CORBA Object Model and uses concepts from that model to define the operation of the Object Request Broker (ORB). The ORB is the basic mechanism by which objects transparently make requests to, and receive responses from, each other on the same machine or across a network. A client need not be aware of the mechanisms used to communicate with or activate an object, how the object is implemented, or where the object is located.