Basic Concepts of Web Services

A web service is a distributed application whose components are deployed and executed on distinct devices. Web services are roughly divided into SOAP-based and REST-style. A SOAP-based service delivered over HTTP can be considered as a special case of a REST-style service.

Acronym SOAP has two meanings: Simple Object Access Protocol or Service Oriented Architecture (SOA) Protocol.

Clients of web services are usually an application that doesn't have a graphical user interface. A client of the SOAP web service sends a SOAP document as a request to a web service, which returns another SOAP document as a response. A client of the REST can send a standard HTTP request to a web service and receive as a response an appropriate XML document.

The web services features:

1. Open infrastructure.
2. Language transparency.
3. Modular design.

WS-I (Web Services-Interoperability) helps software architects and developers to create web services that can interoperate seamlessly despite differences in platforms and programming languages.