Probably in every project built using Materialize all the content is wrapped in a div element with a class called container.
In this example we can see it being used.
The sample content is from Lorem Ipsum.
Removing this div element or removing the container class from it will make the site take up the full width of the browser.
Check the skeleton to see it.
For more details see the beginning of documentation of the grid where this is mentioned.
examples/materializecss/div-container.html
<!DOCTYPE html>
<html>
<head>
<!-- Compiled and minified CSS -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css">
<!--Let browser know website is optimized for mobile-->
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<title>Materialize: div - container</title>
</head>
<body>
<div class="container">
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et
dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip
ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu
fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt
mollit anim id est laborum."
</div>
<!--JavaScript at end of body for optimized loading-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
</body>
</html>
