what does aria-hidden true mean code example

Example 1: aria-hidden in html

When a user views the html page, elements with the hidden attribute should not be visible. 
Aria-hidden attributes indicate that the element and 
ALL of its descendants are still visible in the browser
, but will be invisible to accessibility tools, such as
screen readers.

Example 2: why we use aria hidden true

<p aria-hidden="true">
  Some things are better left unsaid.
</p>