Sun provides the following definition at: services are software components that can be spontaneously discovered, combined, “Web and recombined to provide a solution to the user's problem/request. The Java™ language and XML are the prominent technologies for Web services.” It should be noted that there is broad agreement on what a Web service might be, but no single agreed-upon definition. Many developers will claim that they cannot define what a Web service is, but they know one when they see one. In general, a Web service is a platform and implementation independent software component that can be: Described using a service description language Published to a registry of services Discovered through a standard mechanism (at runtime or design time) Invoked through a declared API, usually over a network Composed with other services One important point is that a Web service need not necessarily exist on the World Wide Web. This is an unfortunate historical naming issue. A Web service can live anywhere on the network, Inter- or intranet; some Web services can be invoked by a simple method invocation in the same operating system process, or perhaps using shared memory between tightly coupled processes running on the same machine. In fact, Web services have little to do with the browser-centric, HTML-focused World Wide Web. Sometimes, the names we choose in the information technology (IT) industry don't make a lot of sense; they simply take on a life of their own. Another important point is that a Web service's implementation and deployment platform details are not relevant to a program that is invoking the service. A Web service is available
Sun provides the following definition at: “Web services are software components that can be spontaneously discovered, combined, and recombined to provide a solution to the user's problem/request. The Java™ language and XML are the prominent technologies for Web services.” It should be noted that there is broad agreement on what a Web service might be, but no single agreed-upon definition. Many developers will claim that they cannot define what a Web service is, but they know one when they see one. In general, a Web service is a platform and implementation independent software component that can be: Described using a service description language Published to a registry of services Discovered through a standard mechanism (at runtime or design time) Invoked through a declared API, usually over a network Composed with other services One important point is that a Web service need not necessarily exist on the World Wide Web. This is an unfortunate historical naming issue. A Web service can live anywhere on the network, Inter- or intranet; some Web services can be invoked by a simple method invocation in the same operating system process, or perhaps using shared memory between tightly coupled processes running on the same machine. In fact, Web services have little to do with the browser-centric, HTML-focused World Wide Web. Sometimes, the names we choose in the information technology (IT) industry don't make a lot of sense; they simply take on a life of their own. Another important point is that a Web service's implementation and deployment platform details are not relevant to a program that is invoking the service. A Web service is available