Web services refers to the standardized way of application-to-application interaction using the XML, SOAP, WSDL and UDDI open standards over internet. It represents an application component to exchange the information between two applications over the network.
A web service works on client server model where client applications can access web services over the network. To access a method or any other resource, client applications use endpoint URIs provided by web services.
Note: Web services are stateless and does not maintain any user session.
Components of Web Services:
Stands for Extensible Markup Language. It is used to tag the data.
Stands for Simple Object Access Protocol. It is used to transfer the data.
Stands for Universal Description, Discovery and Integration. It is used for listing what services are available?
Stands for Web Services Description Language. It is used for describing the services available.
Advantages of web services:
Interoperability is the ability of a system or a product to work with other systems or products without special effort. It is the most important benefit of Web Services. For example a web service created by java can be used by VB or .NET and vice versa.
As we discussed in previous topic a web service is a unit of managed code that can be remotely invoked over internet using HTTP requests i.e. Web services allows us to expose the functionality of our existing code over the network.
Low Cost of Communication:
As we discussed a web service can be invoked over internet using HTTP requests so we can use our existing low-cost internet for implementing web services.
Deployability: Web Services are deployed over standard Internet technologies. This makes it possible to deploy Web Services even over the fire wall to servers running on the Internet on the other side of the globe. Also thanks to the use of proven community standards, underlying security (such as SSL) is already built-in.
Loose Coupling: Web service code and server code are independent to each other which provides loose coupling.