A Web Service uses World Wide Web infrastructure to enable communication between two or more electronic devices. Web service acts as a bridge between various software applications. Primarily, web services are used in business organization to communicate among employees and with clients. Applications access web services through ubiquitous web protocols and data standards such as HTTP, SOAP, WSDL and XML with an internet infrastructure. XML tags the data, SOAP transfers the data, and WSDL describes the available services. Web services couples the advantages from component based development and the web. Moreover, it is a keystone of the Microsoft .Net programming model.
Web services share business logic, data and processes using a programmatic interface across a network instead of using the GUI. The major advantage of web services is that it is highly compatibility, i.e. different applications from different sources can communicate with each other. Web service achieves this through XML based communication. The designing of web services is not based on any of the operating systems or programming language. For instance, Java can communicate with Perl, Windows applications can communicate with UNIX applications.