This document provides an introduction to XML and HTML. It discusses the hierarchical structure of documents and how XML uses tags to describe this structure. It also discusses the different types of elements in XML like divisions and spans. The document provides examples of XML markup and explains some of the rules and premises of XML. It discusses how XML is used in many applications including HTML, RSS feeds, and more. It also briefly introduces the Text Encoding Initiative (TEI) and provides an exercise for students to practice marking up a text with HTML in WordPress by adding tags for emphasis, block quotes, and links.