Hello
CORBA (Common Object Request Broker Architecture) is a standart defined by OMG (Object Management Group), this let distributed object from different languages and OS to communicate. It also provides total transparency in the communication. The IDL (Interface Definition Language) is the tecnology used to describe the interfaces. IDL has your own data types, that are mapped to the data types in other languages. There is an IDL compiler, it generates the codes that do the communication.
But how it works? We have some definitions in a .idl file, in this case Bank-idl (remember to change the filename).