Introduction to Web Services

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

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]

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.

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

• Internet Fundamentals