Web Services
By carefully looking again the preceding example,
you will observe that there is a requestor or a consumer—that is you. There is also a service, the pharmacy store.
The central database of information is the Internet, through which you find the location of the pharmacy. In the example,
when you fire a search in the search engine, your request is wrapped in a structure, whose language is
predetermined and localized, and then passed onto the server running the search engine.
In Web Services, SOAP, UDDI, and WSDL play 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.
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.
This maps to the actual search engine in the example.
The preceding example is just a simplified form of the Web Services environment.
The scope of Web Services includes a lot more.
In short, Web Services in the business world provides a mechanism of communication between two remote systems,
connected through the network of the Web Services. Thus, in case of a merger or an acquisition, companies don't have to
invest large sums of money developing software to bring the systems of the different companies together. Instead they can
just extend the business applications as Web Services and the information systems of different companies can be easily linked.
These business systems then can be accessed by using simple SOAP messages over the normal HTTP Web protocol.