The general structure of XML

The general structure of XML

Define your own tags
In XML, you define your own tags.
If you need a tag <TUTORIAL> or <STOCKRATE>, that's no problem.
DTD or Schema
If you want to use a tag, you'll have to define it's meaning.
This definition is stored in a DTD (Document Type Definition). You can define your own
DTD or use an existing one.
Defining a DTD actually means defining a XML language.
An alternative for a DTD is Schema.
Showing the results
Often it's not necessary to display the data in a XML document. It's for instance
possible to store the data in a database right away.
If you want to show the data, you can. XML itself is not capable of doing so.
But XML documents can be made visible with the aid of a language that defines the
presentation.
XSL (eXtensible Stylesheet Language) is created for this purpose. But the presentation
can also be defined with CSS (Cascading Style Sheets).
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