How Browsers Read HTML

When a browser loads a web page, it reads the HTML from top to bottom and builds an internal model of it called the DOM — the Document Object Model. Every tag becomes a piece of that model, nested inside whichever tag contains it.

You don't write the DOM directly — you write HTML, and the browser constructs the DOM from it as it reads. This is worth knowing now because later tracks (like JavaScript) interact with the DOM directly to change a page after it's loaded, and none of that makes sense without first understanding that HTML becomes the DOM.

The browser is also forgiving. If you forget to close a tag or make a small mistake, most browsers will guess what you meant and display something anyway, rather than refusing to show the page at all. That's convenient, but it also means broken HTML can look fine by accident — this track will teach you to write it correctly from the start.

What does a browser build from HTML as it reads a page?

The browser's internal model of a page, built from HTML, is called the ____.

Browsers always refuse to display a page at all if the HTML has any small mistake in it.