What Is XML?

XML stands for Extensible Markup Language. I know what you're thinking; extensible starts with an "e," not an "x." Well, the reason behind using the "x" instead of "e" is that XML sounds important and "techie."

Now that we have established that the name does not really use the correct letters, we can begin to go over what exactly extensible means.

The extensible part of XML is the fact that XML is much more of a format and set of rules than a language. By that I mean it is a metalanguage. XML is meant to be written in such a way that there are no boundaries for what it can beit just has simple rules. This is because XML is actually a simple form of SGML that allows you to create your own set of tags for different situations, as you will see while you move through the chapter.

Many languages used today are based on XML, such as Extensible HyperText Markup Language (XHTML), Scalable Vector Graphics (SVG), RDF Site Summary (RSS), and Wireless Markup Language (WML).

XML, in its most raw form, does not have conditionals and loop statements like some other languages; it is merely a very strict data holder.

So now you know what its definition is, but how does it work?