What is HTML? — HTML Fundamentals

HTML (HyperText Markup Language) is the standard language used to create the structure of every web page you visit. It is not a programming language — it doesn't calculate or loop — it is a markup language, meaning it wraps content in tags that tell the browser what each piece of content is: a heading, a paragraph, a link, an image, and so on.

Every HTML file is plain text saved with a .html extension, and browsers read that text and render it visually. Here is the smallest valid HTML page:

<!DOCTYPE html>
<html>
  <head>
    <title>My First Page</title>
  </head>
  <body>
    <p>Hello, world!</p>
  </body>
</html>

HTML works alongside two other core web technologies: CSS (which styles how things look) and JavaScript (which adds behavior and interactivity). HTML alone gives you structure and content — no colors, no animations, no logic — just the skeleton of the page.

HTML has evolved over decades, from HTML 1.0 in the early 1990s to the current HTML5 standard, which added semantic elements, native video/audio support, and many form improvements that we'll cover later in this notebook.

By the end of this chapter, you'll be able to write a valid HTML document from scratch and understand exactly why each part of it is needed.