What you should already know
Before you continue you should have some basic understanding of the following:
-- WWW, HTML and the basics of building Web pages
-- Web scripting languages like JavaScript and VBScript
If you want to study these subjects, Go To W3Schools

What is XML?
-- XML stands for EXtensible Markup Language
-- XML is a markup language much like HTML.
-- XML was designed to describe data.
-- XML tags are not predefined in XML. You must define your own tags.
-- XML is self describing.
-- XML uses a DTD (Document Type Definition) to formally describe the data.

The main difference between XML and HTML
XML is not a replacement for HTML.
XML and HTML were designed with different goals:

XML was designed to describe data and to focus on what data is.
HTML was designed to display data and to focus on how data looks.

HTML is about displaying information, XML is about describing information.

XML is extensible
The tags used to markup HTML documents and the structure of HTML documents are predefined. The author of HTML documents can only use tags that are defined in the HTML standard.

XML allows the author to define his own tags and his own document structure.

XML is a complement to HTML
It is important to understand that XML is not a replacement for HTML. In the future development of the Web it is most likely that XML will be used to structure and describe the Web data, while HTML will be used to format and display the same data.

XML in future Web development
We have been participating in XML development since its creation. It has been amazing to see how quickly the XML standard has been developed, and how quickly a large number of software vendors have adopted the standard.

We strongly believe that XML will be as important to the future of the Web as HTML has been to the foundation of the Web. XML is the future for all data transmission and data manipulation over the Web.

How can XML be used?
-- XML can keep data separated from your HTML
-- XML can be used to store data inside HTML documents
-- XML can be used as a format to exchange information
-- XML can be used to store data in files or in databases

XML can keep data separated from your HTML
HTML pages are used to display data. Data is often stored inside HTML pages. With XML this data can now be stored in a separate XML file. This way you can concentrate on using HTML for formatting and display, and be sure that changes in the underlying data will not force changes to any of your HTML code.

XML can also store data inside HTML documents
XML data can also be stored inside HTML pages as "Data Islands". You can
still concentrate on using HTML for formatting and displaying the data.

XML can be used to exchange data
In the real world, computer systems and databases contain data in incompatible formats. One of the most time consuming challenges for developers has been to exchange data between such systems over the Internet. Converting the data to XML can greatly reduce this complexity and create data that can be read by different types of applications.

XML can be used to store data
XML can also be used to store data in files or in databases.
Applications can be written to store and retrieve information from the store, and generic applications can be used to display the data.

"Jani" has participated in a large number of company critical development projects for oil companies like Amoco, ELF, Halliburton, Brown & Root and BP. He has also developed different database systems for governmental institutions like the national library, hospitals, the Norwegian police, and many others.

Today his greatest concern is his Web site at http://www.w3schools.com. This Web site for Web developers is quickly becoming one of the most
popular in the world, with ever increasing visitor traffic.

----------------------------------------------
XML Files Basics, Resources & Examples. All things XML.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~