To grasp the concept of css-bootstrap, focus on understanding the Grid System with rows and width.
Use the .pull-left class to float an element to the left and the .pull-right class to float it to the right.
Start by creating a row with a specified width, then divide it into 2 inner sections with separate widths.
For more information, refer to: Quick floats
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet"/>
<!DOCTYPE html>
<html>
<head>
<!-- Include Bootstrap CSS -->
<link rel="stylesheet"
href=
"https://stackpath.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">
</head>
<body>
<div class="row col-md-12">
<div class="col-md-3">
<span class="pull-left bg-success">left test1</span>
<span class="pull-right bg-warning">right test1</span>
</div>
<div class="col-md-3">
<span class="pull-left bg-info">left test2</span>
<span class="pull-right bg-danger">right test3</span>
</div>
</div>
</body>
</html>