Description:

The HTML <aside> tag is used to represent content that is related to the surrounding content within an article or web page, but could still stand alone in its own right. This type of content is often represented in sidebars.

Example Code:
<p>The Great Barrier Reef is the largest coral reef in the world.</p>
<aside>
<p>The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,600 kilometres over an area of approximately 344,400 square kilometres.</p>
</aside>
Result:

The Great Barrier Reef is the largest coral reef in the world.

Attributes:

None

Global Attributes:

The <aside> tag also supports the Global Attributes in HTML5

Event Attributes:

The <aside> tag also supports the Event Attributes in HTML5