difference

INPUT:

html=<!doctype html>
<html>
<body>
<header>
<div style="color:red" id="nav" >
Nav
<div class="aside"  style="color:blue">
Aside
<div align = "left" class = "section" style = "color:blue">
    <p class="header">
        <span class="main">
            Hi, I have class="main".
        </span>
    </p>
</div> <!--  section-->
</div> <!-- aside -->
</div>  <!--nav -->
Hello
</header>
</body>
</html>

---------------------------------------------------------------------------------------------------
OUTPUT:

<!doctype html>
<html>

<body>
<header>

<nav style="color:red">
Nav
<aside style="color:blue">
Aside

<section align = "left" style = "color:blue">
    <p class="header">
        <span class="main">
            Hi, I have class="main".
        </span>
    </p>

</section>
</aside>
</nav>

Hello
</header>
</body>
</html>