A distributed application component that conforms to standards that make it externally available to web applications. In a typical web services scenario, a business application sends a request to a service at a given URL by using the SOAP protocol over HTTP. The service receives the request, processes it, and returns a response. An example of a web service is a stock quote service, in which the client application sends a request for the current price of a specified stock, and the web service responds by returning the stock price.
A web service provides a set of methods that can be called by your applications. The methods are described in the web service's WSDL file. When you add a web service in the Services window, the IDE reads the web service's WSDL file and creates a set of method stubs for you that you can use in your applications.