html section tag

HTML
<html>
<head></head>
<body>
    <header></header>
    <section>
        <h1>ffffff</h1>
        <div>
            <span></span>
        </div>
        <div></div>
    </section>
    <footer></footer>
</body>
</html><section id="header"> Name of section
	<div class="container">
		<div class="row">
			<div class="col-xs-12"></div>
		</div>
	</div> 
</section>

<section id="main-content"> Name of section
	<div class="container">
		<div class="row">
			<div class="col-xs-6"></div>
			<div class="col-xs-6"></div>
		</div>
	</div> 
</section>

<section id="footer"> Name of section
	<div class="container-fluid">
		<div class="row">
			<div class="col-xs-4"></div>
			<div class="col-xs-4"></div>
			<div class="col-xs-4"></div>
		</div>
	</div> 
</section>
Source