There are 2 ways I found to mark up a sidebar:
<aside id="sidebar">
<section id="widget_1"></section>
<section id="widget_2"></section>
<section id="widget_3"></section>
</aside>
and
<aside id="sidebar">
<div class="widget" id="widget_1"></div>
<div class="widget" id="widget_2"></div>
<div class="widget" id="widget_3"></div>
</aside>
Please tell me what is difference between both approaches and which one must be used?