Code and Syntax For Fun

Like most good ideas, XML is basically a very simple idea that can be put to good use in many situations. It is not intended to be a direct replacement for the general-purpose markup that is provided by HTML describing how content should be displayed. Instead XML ofers a means to define and construct other custom markup languages with tags you name yourself and rules which you define for how those tags can be used. So because XML is a language that describes other language it is termed as being a 'meta-language'.

The two words that should be most strongly associated with any definition of XML are 'structure' and 'data'.

Custom markup languages constructed in XML will arrange data in a structured manner so it can be accessed and manipulated in a variety of ways. For instance, you could use XML to create a custom markup language called 'EruptML' to describe the data on all active volcanoes.

Using data in a XML document often employs other XML technologies which are explored in the later topics.