Chapter 1: What is XML?

Overview

This chapter provides a brief summary of what XML is. The abbreviation XML refers to eXtensible Markup Language, which means that XML is extensible or changeable . HTML (Hypertext Markup Language), on the contrary, is a non-extensible language and is the default language that sits behind many of the web pages in your web browser, along with numerous other languages.

HTML does not allow changes to web pages. HTML web pages are effectively frozen in time when they are built and cannot be changed when viewed in a browser.

Internet Explorer and Netscape are browsers used for viewing websites on the Internet.

XML, on the other hand, allows generation of web pages on the fly. XML allows storage of changeable data into web pages that can be altered at any time besides runtime. XML pages can also be tailored in look, feel, and content, and they can be tailored to any specific user looking at a web page at any point in time.

In this chapter you learn:

• What XML is

• What XSL is

• The differences between XML and HTML

• Basic XML syntax

• The basics of the XML DOM

• Details about different browsers and XML

• The basics of the DTD (Document Type Definition)

• How to construct an XML document

• Reserved characters in XML

• How to ignore the XML parser

• What XML namespaces are

• How to handle XML for multiple languages

Lets begin by comparing XML with HTML, the Hypertext Markup Language.