What it is
Reads the meta tags that tell search engines and social platforms how to present the page: title, description, preview image, author, canonical URL and linked social accounts. Most follow either the Open Graph or Twitter Card conventions.
Why it matters
This is how a site describes itself when it thinks a machine is reading. The preview title and description often differ from the on-page copy, and the tags regularly name authors, social accounts or a parent organisation that appear nowhere else.