Intro is the beginning part of the news. It explains the news in brief. It contains less information than lead.
Lead is the beginning of the news sentence that explains essential information. It contains more detail information than intro. It set the tone and entice people to continue reading the news.
Example:
Intro:
Diego Maradona dies after suffering heart failure.
Lead:
Argentina soccer legend Diego Maradona, who has died aged 60, succumbed to heart failure, a source from the Argentinian Justice Ministry present at the time of his autopsy told CNN en Español on Wednesday.
https://www.google.com/amp/s/amp.cnn.com/cnn/2020/11/25/football/diego-maradona-death-argentina-spt-intl/index.html