Web Services

The web services concept being championed by computing giants like Sun, Oracle, HP, Microsoft, and IBM doesn't contain many new ideas, but it is a great step towards simple access to software over the network. By promoting standards-based communication, web services might change the way we build websites.

Web services make software functionality available over the Internet so that programs like PHP, ASP, JSP, JavaBeans, the COM object, and all our other favorite widgets can make a request to a program running on another server (a web service) and use that program's response in a website, WAP service, or other application.

Component Technologies of Web Services
Consider a scenario in which you need to locate a particular pharmacy store in your area. You would not go out on the road and ask every person you met the way to the store. You might, instead, refer the Web site of the pharmacy on the Internet. If you knew the pharmacy's Web site, you would look it up directly and find the location through the store locator link. If not, you would go to a search engine and type out the name of the pharmacy in the language that the search engine was meant to recognize. After getting the location, you would find the directions to the store, and then go to the store.

In Web Services, SOAP, UDDI, and WSDL represent the roles mentioned in these steps.

SOAP (Simple Object Access Protocol) is the method by which you can send messages across different modules. This is similar to how you communicate with the search engine that contains an index with the Web sites registered in the index associated with the keywords.

UDDI (Universal Description, Discovery, and Integration) is the global look up base for locating the services. In the example mentioned earlier, this is analogous to the index service for the search engine, in which all the Web sites register themselves associated with their keywords. It maintains a record of all the pharmacy store locations throughout the country.

WSDL (Web Services Definition Language) is the method through which different services are described in the UDDI.

Summarize: A Web Service is
* A programmable application, accessible as a component via standard Web protocols,
* Uses standard Web protocols like HTTP, XML and SOAP,
* Works through existing proxies and firewalls,
* Can take advantage of HTTP authentication,
* Encryption for free with SSL,
* Easy incorporation with existing XML messaging solutions,
* Takes advantage of XML messaging schemas and easy transition from XML RPC solutions,
* No conflict between proprietary component based solutions like CORBA and COM,
* Combines the best aspects of component-based development and the Web, and Available to a variety of clients (platform independent).

Business Aspects of Web Services
Web Services in the business world, in the most simplistic fashion, provides a mechanism of communication between two remote systems, connected through the network of the Web Services. The business applications as Web Services, the information systems of different companies can be linked. These business systems then can be accessed by using simple SOAP messages over the normal HTTP Web protocol.

There are many more important uses of Web Services. These, again, depend on the requirement of your company. Interested enough to find out more? In our next article, you will learn about the architecture of Web Services, the technology organization, the protocols used, and the basic steps involved in building a Web Services application.