Before we get too much further along, let's make sure we are all on the same footing regarding the basic terminology that we will deal with in this tutorial.
XML: "XML is the Extensible Markup Language. It is designed to improve the functionality of the Web by providing more flexible and adaptable information identification." (http://www.ucc.ie/xml/#acro)%br%%br%In other words, XML is a method for describing your data. For the purpose of this tutorial, we will not be directly manipulating any XML. Instead, we will examine the XML resulting from our scripts. The libraries and protocols we will use through this tutorial will handle the XML manipulation for us.%br%%br%
SOAP: Simple Object Access Protocol. "SOAP is a lightweight protocol for exchange of information in a decentralized, distributed environment. It is an XML based protocol that consists of three parts: an envelope that defines a framework for describing what is in a message and how to process it, a set of encoding rules for expressing instances of application-defined datatypes, and a convention for representing remote procedure calls and responses." (http://www.w3.org/TR/2000/NOTE-SOAP-20000508/)%br%%br%SOAP is what you are here for. We will develop both a client and a server for our SOAP service. In this tutorial, we will be using the NuSOAP library. (http://dietrich.ganx4.com/nusoap/index.php)%br%%br%
WSDL: "WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information." (http://www.w3.org/TR/wsdl)%br%%br%As with XML, we will not be directly any WSDL documents. The wonderful NuSOAP library will generate WSDL documents for us. What you need to know about WSDL is that it is a document that describes a Web Service. It can tell a client how to interact with the Web Service and what interfaces that Web Service provides.%br%%br%
Client: We will define a Client as a script that uses a Web Service.%br%%br%
Server: Conversely, a Server will be defined as a script that provides a Web Service.