This document provides an introduction to HTML and building basic websites. It explains that HTML stands for "hypertext markup language" and is used to build websites. The document then gives an example of a simple HTML file structure and tags like <html>, <head>, <title>, <body>, <h1>, <p>, etc. It demonstrates how to write the code for a basic "Hello World" website and includes an explanation of each part of the code. The document concludes by listing some common HTML tags that can be used to format text and insert images and links.