A Brief Description on XML >> wickcentral.com

Based on the same parent technology as Hyper Text Markup Language

It's designed to better handle the task of managing information that the growth of the internet now requires

What's wrong with HTML?

Its simple, easy to use but vague! HTML's simplicity limits its power.
It does not give information about the content of the web page. This makes it hard to reuse the information in another context.
HTML is limited when it come to formatting and dynamic content- many extensions have been tacked on, usually in a hurry in order to add power.
Some of the above mentioned extensions only work in some browsers and thus represents a major limitation in terms of portability.

Why is XML Powerfull?

Design ones own custom markup language- create other languages
The tags actually describe the content they contain
Reuse Data- because the tag identifies the data, it can be reused
Applications can be programmed to entract specific information identified by specific tags

XML and E-Commerce

Due to XML's inherent platform independence and its ability to "self-define" itself for each new environment, Microsoft.NET and the J2EE development environments are both relying heavily on XML for data exchange and interoperability
XML e-commerce applications are very effective when deployed in a multi-tiered ("n-tier") archetecture. Here, the internal modules of applications are comprised of three tiers:
1. front-end edge services,
2. mid-tier application logic and
3. back-end database services.
They are decoupled and distributed into dedicated servers as necessary, to improve performance, availability and scalability.
XML is the glue used to integrate these various tiers of the e-commerce application
XML e-commerce and inter-application Web services involve more data-rich interactions and processor-intensive security encryption/decryption
XML is more complex and flexible than HTML and therefore its markup is more verbose and more computationally intensive to process. Thus server performance becomes even more critical

A scalable computing architecture for high-volume e-commerce