Why do we need .Net Web Services?

We have a number of heterogeneous technologies available on internet. The demand for reusable components across platforms and programming languages are high. Most of the components have the limitation that they can't share or exchange data across different platforms, they are mostly language specific or platform specific. The technologies like COM, RMI, CORBA etc. contributed best to fulfill requirements to some extent, but components result from these said technologies are mostly either language specific or platform specific. 

To avoid above problem, we need to have web services. Through web services we have overcome the problem of interoperability between languages and platforms. Web services uses SOAP as transport protocol which uses a text based messaging model, i.e. XML to communicate between disparate systems.