soap, uddi, wsdl. xml definitions

SOAP (Simple Object Access

Protocol):

It is a way for a program running in one kind of operating system such as (Windows 2000) to communicate with a program in the same or another kind of an operating system (such as

Linux) by using the World Wide Web's Hypertext Transfer Protocol (HTTP) and its Extensible

Markup Language XML as the mechanisms for information exchange.

Since Web protocols are installed and available for use by all major operating system Platforms, HTTP and XML provide an already at-hand solution to the problem of how Programs running under different operating systems in a network can communicate with each other. SOAP specifies exactly how to encode an HTTP header and an XML file so that a program in one computer can call a program in another computer and pass it information. It also specifies how the called program can return a response.

An advantage of SOAP is that program calls are much more likely to get through firewall servers that screen out requests other than those for known applications (through the designated port mechanism). Since HTTP

requests are usually allowed through firewalls, programs using SOAP to communicate can

be sure that they can communicate with programs anywhere.

UDDI: (Universal Description, Discovery, and Integration)

(Universal Description, Discovery, and Integration) is an XML -based registry for businesses worldwide to list themselves on the Internet. Its

ultimate goal is to streamline online transactions by enabling companies to find one another on the Web and make their systems

interoperable for e-commerce. UDDI is often compared to a telephone book's white, yellow, and green pages. The project allows businesses to list themselves by name, product, location, or the Web services they

offer.Microsoft, IBM, and Ariba spearheaded UDDI. The project now

includes 130 companies, including some of the biggest names in the corporate world. Compaq, American Express, and Ford Motor

Company are all committed to UDDI, as is Hewlett-Packard whose own XML-based directory approach, called  e-speak, is now being

integrated with UDDI. While the group does not refer to itself as a standards body, it does offer a framework for Web services integration.

The UDDI specification utilizes World Wide Web Consortium (W3C) and Internet Engineering Task Force (IETF) standards such as

XML, HTTP, and Domain Name System (DNS) protocols. It has also adopted early versions of the proposed Simple Object Access Protocol

(SOAP) messaging guidelines for cross platform programming.

In November 2000, UDDI entered its public beta-testing phase. Each of its three founders - Microsoft, IBM, and Ariba - now operates a registry server that is interoperable with servers from other members. As information goes into a registry server, it is shared by servers in the other businesses. The UDDI beta is scheduled to end in the first quarter of 2001. In the future, other companies will act as operators of the UDDI Business Registry.

WSDL : (Web Services Description Language) :

The Web Services Description Language (WSDL) is an X M L-based language used to describe the services a business offers and to provide a way for individuals and

other businesses to access those services electronically. WSDL is the cornerstone of the Universal Description, Discovery, and

Integration (UDDI) initiative spearheaded by Microsoft, IBM, and Ariba. UDDI is an XML-

based registry for businesses worldwide, which enables businesses to list themselves and their services on the Internet. WSDL is

the language used to do this.

WSDL is derived from Microsoft's Simple Object Access Protocol

(SOAP) and IBM'sNetwork Accessible Service

Specification Language (NASSL). WSDL replaces both

NASSL and SOAP as the means of expressing business services in the

UDDI registry.

XML (Extensible Markup Language)

XML is a markup language for documents containing structured information. Structured

information contains both content (words, pictures, etc.) and some indication of what

role that content plays (for example, content in a section heading has a different meaning

from content in a footnote, which means something different than content in a figure caption or content in a database table, etc.). Almost all documents have some structure.

A markup language is a mechanism to identify structures in a document. The XML specification

defines a standard way to add markup to documents.