In the following example, let's define an IDL interface to work with a client-server application. The client application invokes a method of the server program and gets the response from the server method.

The IDL interface has the interface name followed by the .idl extension:

//Employee.idl
module org {
  module admin {
    module hr {
      module employee {
        interface Registry {
          string register();
        };
      };
    };
  };
};