Run Example

Edit This Code:
<!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="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script>
</head>
<body>

 <button class="btn"> Button </button>
 <button class="btn btn-default"> Default </button>
 <button class="btn btn-primary"> Primary </button>
 <button class="btn btn-success"> Success </button>
 <button class="btn btn-info"> Info </button>
 <button class="btn btn-warning"> Warning </button>
 <button class="btn btn-danger"> Danger </button>
 <button class="btn btn-link"> Link </button>

</body>
</html>
Result: