Structural blocks of the site in HTML

The structural blocks of the site have standard names. The upper part of the site is called header, the lower part is footer, the main part with text is content, and the side part is sidebar. And the general block in which the entire site is located is called wrapper:

<div id="wrapper">
	<div id="header">
		header
	</div>
	<div id="content">
		content
	</div>
	<div id="sidebar">
		sidebar
	</div>
	<div id="footer">
		footer
	</div>
</div>

Often the main text and sidebars are combined into one block called container:

<div id="wrapper">
	<div id="header">
		header
	</div>
	<div id="container">
		<div id="content">
			content
		</div>
		<div id="sidebar">
			sidebar
		</div>
	</div>
	<div id="footer">
		footer
	</div>
</div>

There may be more than one sidebar. Often, websites have two sidebars - one to the left of the content, and the second to the right:

<div id="wrapper">
	<div id="header">
		header
	</div>
	<div id="container">
		<div id="left">
			left sidebar
		</div>
		<div id="content">
			content
		</div>
		<div id="right">
			right sidebar
		</div>
	</div>
	<div id="footer">
		footer
	</div>
</div>