Is a way of breaking up the page into boxes that can be moved and styled using CSS
<!DOCTYPE html>
<html>
<head>
<title>My website</title>
<meta charset="UTF-8">
</head>
<body>
<div>
<section>
<h2>Latest Deals</h2>
<h3>See latest holiday deals here</h3>
<article>
<h4>Holiday 1</h4>
<p>A lovely break in spain</p>
</article>
</section>
</div>
</body>
</html>