HTML <aside> tag

The \<aside> tag has two purposes, depending on whether it is inside an \<article> element or not.
When the \<aside> element is used inside an \<article> element, it should contain information that is related to the article but not essential to its overall meaning. 
When the \<aside> element is used outside of an \<article> element, it acts as a container for content that is related to the entire page.