CORBA (Common Object Request Broker Architecture) is a standard for software components. CORBA defines APIs, communication protocol, and object/service information models to enable heterogeneous applications written in various languages running on various platforms to interoperate. CORBA therefore provides platform and location transparency for well-defined objects, which are the fundamental underpinnings of any Distributed computing platform.
CORBA is created and controlled by the Object Management Group (OMG).
In a general sense CORBA "wraps" code written in another language into a bundle containing additional information on the capabilities of the code inside, and how to call it. The resulting wrapped objects can then be called from other programs (or CORBA objects) over the network. In this sense CORBA can be considered as a machine-readable documentation format, similar to a header file but with considerably more information.
CORBA uses an interface definition language, to specify the interfaces that objects will present to the world. CORBA then specifies a "mapping" from IDL to a specific implementation language like C++ or Java. This mapping precisely describes how the CORBA data types are to be used in both client and server implementations. Standard mappings exist for C, C++, Smalltalk, Java and Python. There are also non-standard mappings for Perl and Tcl implemented by ORBs written for those languages.
The CORBA IDL is only one example of an IDL.
CORBA is most widely used with C++ or Java, but it is also usable with Smalltalk, C, Python, Perl and Tcl, and therefore allows easy interoperability between all those languages.