Web service is any piece of software that makes itself available over the internet and uses a standardized XML messaging system. Because all communication is in XML, web services are not tied to any one operating system or programming language--Java can talk with Perl; Windows applications can talk with Unix applications.
Here are the benefits of using Web Services
Web Services allows you to expose the functionality of your existing code over the network. Once it is exposed on the network, other application can use the functionality of your program.
Web Services allows different applications to talk to each other and share data and services among themselves. So, Web services is used to make the application platform and technology independent.
Web Services uses standardized industry standard protocol for the communication. This standardization of protocol stack gives the business many advantages like wide range of choices, reduction in the cost due to competition and increase in the quality.
Web Services uses SOAP over HTTP protocol for the communication, so you can use your existing low cost internet for implementing Web Services. This solution is much less costly compared to proprietary solutions like EDI/B2B.
Web Services Behavioral Characteristics
• Loosely coupled
• Coarse-grained
• Ability to be synchronous or asynchronous
• Supports Remote Procedure Calls (RPCs)
• Supports document exchange
Web Services Architecture
1. Web Service Roles
There are three major roles within the web service architecture: • Service provider: This is the provider of the web service. The service provider implements the service and makes it available on the Internet. • Service requestor This is any consumer of the web service. The requestor utilizes an existing web service by opening a network connection and sending an XML request. • Service registry This is a