Reprintable Article: Permission is granted for following article to forward, reprint, distribute, use for ezine, newsletter, website, offer as free bonus or part of a product for sale as long as no changes are made and byline, copyright, and resource box is included. ---------------------------------------------------------- What is a Web Service?By Stephen Bucaro
Try to find an article on Web that explains, in plain English, what a "Web Service" is and you'll be going around in rhetorical circles with no simple explanation, and no examples. Most articles start out with some ambiguous explanation like: "Web services identified with WSDL and UDDI protocols make functionality available over Internet using SOAP encapsulated in XML envelopes" and then articles start spewing out programming code. Examples of programming code don't help if you don't have an overview of what a Web Service is.
David Berlind in his article "What are Web services anyway?" for ZDNet.com says, "At last fall's Gartner Symposium I asked several attendees -- presumably C-level technology executives -- if they could give me a definition of Web services ... No one knew. Before session's end, over half attendees had left because they were expecting a discussion about something else."
When you do find examples of Web Services, they are applications like; retrieving a stock quote, finding best price for a product, saving an appointment to a calendar, or validating a credit card number. These are all things that we have been doing on Web for years. So, what's big deal about Web Services?
Web services can be thought of as an evolution of software components concept. For example, say you have several different word processors on your computer, or on your network. In early days of software, each application needed to contain it's own separate spell checking code. With components, spell checking function is programmed into a separate module that can be shared by several different word processor programs. Every programmer doesn't have to write their own spell checking code, they can license use of a spell checking module from a components vender.
The same thing is possible over internet using DCOM, CORBA, JavaBeans, etc. But these technologies were all created by different organizations. The components find it difficult to communicate with each other. It requires a lot of information sharing and pre-planning to make these components work together. "Web Services" is a set of vendor-neutral specifications and protocols developed by standards organizations such as OASIS and W3C.
Using these standard protocols, Web sites can share Web applications in a manner similar to how a spell checking component can be shared between word processor programs. Every Web site does not have to write it's own program code to retrieve a stock quote, find a best price, saving an appointment to a calendar, or validate a credit card number. They can license use of these functions from Web Service providers.
From human Web users point of view, Web still appears to work same. There is nothing new. That is why it's so difficult to find a simple explanation of "Web Services". The new technology of Web Services is what goes on under hood. That's why most articles about subject jump right into programming code. Many "Web Service" articles are just articles about XML.