Information that is stored in an XML format has the same basic structure as HTML.
HTML uses a set of markup tags (words surrounded by '<' and '>')to describe
the format of a web page, and the browser recognises these elements and knows how to
display the content that appears between the opening and closing tags.
HTML provides a fixed set of tags for describing the appearance of a document.
XML, on the other hand, allows developers or web-site designers to create element
names that reflect the purpose of the application. For example, an XML document
storing information about books might have the following structure:
MicroMac recognised the value of XML as a storage format for structured data
when XML was still an emerging standard. Working in an environment where
test results were traditionally stored in ASCII files, MicroMac designed a
Test Data Collection and Analysis system based on an XML test results file.
An early implementation of this format
illustrates the self-describing nature of XML.
The representation of an XML document in a browser is determined by the
web-site or application developer. XML transformations are often used
to generate HTML for rendering in a browser. MicroMac have implemented a
web-based operation card manager which uses XML as the document storage format
and allows standard HTML content to be included in the operation details.