This document provides an introduction to HTML and CSS. It breaks down what HTML and CSS are used for. HTML is used to provide the content, structure and semantics of a web page, while CSS is used to style and lay out the presentation of HTML elements. The document explains HTML tag structure, document structure and common doctypes. It also demonstrates basic CSS syntax and structure for rules. Hexadecimal color codes are briefly covered. Examples are provided and additional online resources listed for more comprehensive information on HTML and CSS.