Bootstrap requires a containing element to wrap site contents. In bootstrap, there are two container classes .container and .container-fluid. The bootstrap .container-fluid class provides a full-width container, spanning the entire width of the viewport. Use the .container-fluid class to create a full-width container, that will always span the entire width of the screen (width is always 100%).
.container-fluid class Example
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap container-fluid class Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container-fluid bg-primary text-white p-4 mt-4">
<h1>Bootstrap .container-fluid class</h1>
<p>This content is inside a .container-fluid class.</p>
<p>The .container-fluid class provides a full width container, spanning the entire width of the viewport.</p>
</div>
</body>
</html>
