Introduction to Web Services

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This is an introductory tutorial about the fundamental elements of Web services.

What are Web Services?[edit]

Web services

  • are application components
  • communicate using open protocols
  • are self-contained and self-describing
  • can be discovered using UDDI
  • can be used by other applications
  • based on XML

According to the W3C, the World Wide Web Consortium, two major classes of Web services exist:

  • REST-compliant Web services: the primary purpose of this kind of Web service is to manipulate XML representations of Web resources using a uniform set of "stateless" operations
  • Arbitrary Web services: these Web services may expose an arbitrary set of operations.[1]

How Does it Work?[edit]

The basic Web services platform is XML + HTTP.

The HTTP protocol is the most used Internet protocol.

XML provides a language that can be used between different platforms and programming languages and still expresses complex messages and functions.

Platform elements[edit]

Web services platform elements are

  • SOAP (Simple Object Access Protocol)
SOAP is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks.
  • UDDI (Universal Description, Discovery, and Integration)
UDDI is a platform-independent, Extensible Markup Language (XML)-based registry for businesses worldwide to list themselves on the Internet and a mechanism to register and locate web service applications.
  • WSDL (Web Services Description Language)
WSDL is an XML-based language that provides a model for describing Web services.

We will explain these topics later in the tutorial. Thank you


  1. "Relationship to the World Wide Web and REST Architectures". Web Services Architecture. W3C. Retrieved 2011-04-22.