If u look for developing a c++/fortran/c/java etc application running
in a single host environment its fine.

But how about when u want to develop an application part of whoes logic
could be in a flying plane or satellite up in the sky and part at its
control center down on earth. Making it easy how about reservation
systems or banking systems whoes logic is partially distributed across
hosts of computer?

Here comes the problem. Either each systems should be uniformly
developed using same language / computer to enable interactions. Also u
need to take care of connection management, connection opening/closing,
 U need to put in lots of efforts to enable fault tolerance,
load-balancing etc. Then their are issues to be managed related to
location of each of these hosts etc.

the tech like CORBA, COM/DCOM/ etc. provides u a platform to develop
such an application with the relatively same ease as any standalone
systems.

These tech/softwares takes care of networking stuff, and provide an
abstraction that enables u to develop application in a completely
transparent manner.

A programmer doesnt requires to write any code for
connecting/disconnecting remote objects. He is required to address any
issue arising out of "what if various objects of the systems are
developed using diff languages on diff platforms".

In other words it provides complete interoperability among objects
written in any platform (read os and language).

And also because CORBA comes with host of standard services, so makes
code portable across any corba implementations (albeit with a trivial
efforts).

Let me know if u still dont follow.