hi all,
  I am new to web-services and infact got the concept from
 seminars.As per my understanding till now with the help of
 the webservices i can do interact among various applications written in various languages.Is it doing the
 same job as corba will do?Please give me the details
 of the sources where i can find the same.
 regards vicky

Web services is the notion of exposing services between disparate trading partners to enable them to collaborate. Since we have two different companies talking, the protocols involved typically fall into publically accessible ones like HTTP and XML content. Web services does not really specify the underlying language/application (except in vendor specific frameworks). The fact that it only allows apps in different languages to communicate is a happy coincidence. Particular instances of web service frameworks range from Microsoft's .NET, HP's eSpeak and Sun's SunONE.

CORBA is a particular instance of framework (in this case from OMG) for interoperability. Corba specifies a complete framework from protocol to interfaces to services for interoperability between different languages. It does not explicitly address the notion of collaboration between trading partners.

There is an overlap in the possible usage between one and another. However, CORBA is a more specific one and web services is more of a general category.

francis!

The issue of how new is web services is being hotly debated.

What web services provide that CORBA and other distributed technlogies do not is a standard format for message exchange and a ubiquitous communication protocol.

e.g. CORBA systems are built on IIOP, SOAP messages are transmitted over HTTP bypassing problems with firewalls that have plagued IIOP etc.

Also Web Services are not replacing CORBA, EJB, or COM. They are in fact allowing service providers to expose the logic contained in these components, and avoid the challenges of converting between them.

e.g. SOAP 2.2 currently provides mappings from java2XML,
and IDL2XML.

What this all means is that the web services paradigm provides a foundation to shift from client/server computing to peer-to-peer commputing.

Saajid

I agree, these are good points. I would add though that you probably would still be doing local calls with CORBA or RMI, this benchmark is very interesting. You might especially note the conclusion stating that SOAP was about 10x slower than RMI.