HTML is the structure of every webpage; it’s like the floorplan for an apartment or the outline for a blog post. It's written in almost-human-readable elements called tags, of which there are many:
<html>
<title>A basic webpage</title>
<h1>This is a webpage.</h1>
<p>Not much more to say about it</p>
</html>HTML has 140+ of these built in tags that mean something specific to your browser.