<div id="left-sidebar">

<ul>

<li>Sidebar item 1</li>

<li>Sidebar item 2</li>

<li>Sidebar item 3</li>

</ul>

</div>

Remember, you can always nest divs inside one another, so you can also nest ids. On top of this, you can apply ids to the majority of elements in HTML, not just divs, let’s see an example of nested ids and ids on elements other than divs: