This part is inside a .container-fluid class.
The .container-fluid class provides a full width container, spanning the entire width of the viewport.
<!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css"> <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script> <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script> </head> <body> <div class="container-fluid"> <h1>My First Bootstrap Page</h1> <p>This part 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>