Before starting to learn XML one must know what XML is. XML is a mark up language similar to HTML that is capable of holding data or information. XML does not display the information and it stands for eXtensible Mark up Language. As in HTML, XML uses tags in its mark up, but are not defined. All tags in XML must be defined by the user or programmer and is used for the storage or transport of data. To take this concept further, XML does not do anything, it is simply a vessel to hold the information; HTML is used for displaying data and information. This makes it flexible with a variety of computer setups.
XML's key features allow it to operate within any platform and with virtually any program or application. This simplifies the transport of data between differing platforms as well as separating the data and information from HTML.
In other words, XML is plain text. Software that can read, interpret, and use plain text can also use XML, but XML specific applications can treat XML tags specifically as they are intended by their programmers. It is important to remember that XML is not intended to replace HTML but can and does work in conjunction with HTML and HTML applications.
Perhaps the simplest explanation of XML is this: XML is a mark up language independent of software and hardware specifics that can be used to transport and store data. XML is now an integral part of the Internet much as was the importance of HTML in the Internet's creation and implementation.
XML's key features allow it to operate within any platform and with virtually any program or application. This simplifies the transport of data between differing platforms as well as separating the data and information from HTML. In addition, XML enables easier and faster file sharing creating an easier environment for data to be more accessible by more people and applications.
For more information on XML:
XML Tutorial from the W3C
A Technical Introduction to XML
A Simple XML Explanation and Tutorial
A Gentle Introduction to XML
Advanced Concepts in XML
Techniques for Using XML
Advanced XML Validation
A List of Links to Free XML Tools and Software
A Guide to XML Software
IBM XML Classes
Preparing for XML Certifications
An Introduction to Using Scripting Languages with XML
Using XML as a Scripting Language