Web service is a platform-independent, low-coupling, self-contained and programmable Web-based application. It can be described, published, discovered, coordinated and configured by using open XML (a subset of standard generalized markup language) standards to develop distributed and interoperable applications.
Web service technology enables different applications running on different machines to exchange data or integrate with each other without the help of additional specialized third-party software or hardware. No matter what language, platform or internal protocol is used, applications implemented according to the Web service specification can exchange data with each other. Web service is a self-describing, self-contained and available network module, which can perform specific business functions. Web services are also easy to deploy because they are based on some traditional industry standards and some existing technologies, such as XML and HTTP subsets under standard generalized markup language. Web services reduce the cost of application interface. Web services provide a general mechanism for business process integration between the whole enterprise and even multiple organizations.