What is a Web Service?
The Web Services are the business logic components which provide the functionality via the Internet using standard protocols like HTTP.
The Web Services uses the Simple Object Access Protocol (SOAP) in order to expose the business functionality. The SOAP defines a standardized format in the XML which can be exchanged between the two entities over standard protocols like HTTP. The SOAP is platform independent so the consumer of a Web Service is therefore completely shielded from any implementation details about the platform exposing the Web Service. For consumer it is simply a black box of send and receives XML over HTTP. Hence any web service hosted on windows can also be consumed by UNIX & LINUX platform.