HTML Introduction

HTML (HyperText Markup Language) is the language that describes the content of every web page. It is not a programming language: it uses tags to label pieces of content as headings, paragraphs, links, images and so on. The browser reads those tags and shows the page.

A tag is a keyword in angle brackets. Most come in pairs — an opening tag and a closing tag with a slash — wrapped around content:

<h1>This is a heading</h1>
<p>This is a paragraph.</p>

Change the text above and press Run to see the result. That is the whole idea: write a tag, run it, see what it does.