SOAP (Simple Object Access Protocol) is a simple protocol

for exchange of information. It is based on XML and

consists of three parts: a SOAP envelope (describing what's

in the message and how to process it); a set of encoding

rules, and a convention for representing RPCs (Remote

Procedure Calls) and responses.

UDDI (Universal Description, Discovery, and Integration) is

a specification designed to allow businesses of all sizes

to benefit in the new digital economy. There is a UDDI

registry, which is open to everybody. Membership is free

and members can enter details about themselves and the

services they provide. Searches can be performed by company

name, specific service, or types of service. This allows

companies providing or needing web services to discover

each other, define how they interact over the Internet and

share such information in a truly global and standardized

fashion.

WSDL (Web Services Description Language) defines the XML

grammar for describing services as collections of

communication endpoints capable of exchanging messages.

Companies can publish WSDLs for services they provide and

others can access those services using the information in

the WSDL. Links to WSDLs are usually offered in a company?s

profile in the UDDI registry.