Chapter 15. Web Services Overview
The World Wide Web has opened up distributed computing on a large scale. However, normal web pages only allow interaction between the client browser and the web server hosting the web page. The goal of web services is to create web-based applications that interact with other applications with no user interface. If you’re a web page developer, having such web services available can greatly increase your productivity. Imagine, for instance, you are creating a web site for a stock brokerage firm. Rather than having to integrate your back-end database with all the various databases of the different stock exchanges, your application can simply communicate with their web services, exchanging data in XML format.
Web services are similar to web pages. The principal difference is that a web page is intended for viewing by a person, while a web service is used strictly for one program to interact with another and has no user interface.
Web services are entirely independent of the operating system or programming language used on either the server or the client side. Unlike previous technologies for distributed computing (such as DCOM), web services make it unnecessary for either end of the connection to be running the same operating system or to be programmed in the same language. For example, the server code might be written in VB.NET on Windows 2000 while the client is C++ running on a Unix machine, or vice versa. In other words, while previous technologies ...