<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Simple</title>
<link rel="stylesheet" type="text/css" href="css/style.css">
</head>
<body>
<header>
<div class="box">
<h1>Product name</h1>
<div class="list_h">
<ul>
<li>Put on this page information about your product</li>
<li>A detailed description of your product</li>
<li>Tell us about the advantages and merits</li>
<li>Associate the page with the payment system</li>
</ul>
</div>
<div class="banner">
<img src="../image/banner.png">
</div>
</div>
</header>
</body>
</html>
.holder { overflow:hidden;}
.banner { float:right;}
<div class="holder">
<div class="banner">
<img src="../image/banner.png">
</div>
<div class="box">
<h1>Product name</h1>
<div class="list_h">
<ul>
<li>Put on this page information about your product</li>
<li>A detailed description of your product</li>
<li>Tell us about the advantages and merits</li>
<li>Associate the page with the payment system</li>
</ul>
</div>
</div>
</div>