The <aside> tag defines some content aside from the content it is placed in.
The aside content should be related to the surrounding content.
The numbers in the table specify the first browser version that fully supports the element.
The <aside> tag is new in HTML5.
Tip: The <aside> content could be placed as a sidebar in an article.
The <aside> tag also supports the Global Attributes in HTML.
The <aside> tag also supports the Event Attributes in HTML.
HTML DOM reference: Aside Object
Most browsers will display the <aside> element with the following default values: