Imagine that while driving through unknown territory, you could ask an onboard car computer for directions to the nearest gas station.
For that to be possible, the markup language used for this application must be specific not just in terms of document structure but also about the actual content contained within the documents.
XML (eXtensible Markup Language) is a meta-markup language that expressly separates content from presentation.
Using user-defined XML elements, or tags, XML documents provide meaning to the data contained in these documents. Presentation of XML documents may take several different formats, including rendering an XML document in a browser.
This module defines XML, discusses its origins and applications, and describes the evolution of markup and metalanguages.

By the end of the module, you will have the skills and knowledge necessary to:

1. Describe markup languages
2. Describe metalanguages
3. Describe the limitations of HTML
4. Define XML
5. List the goals of XML
6. Describe approaches to using XML