man Parse::MediaWikiDump::link (3): Object representing a link from one article to another

ABOUT

This object is used to access the data associated with each individual link between articles in a MediaWiki instance.

$link->from: Returns the article id (not the name) that the link orginiates from.
$link->namespace: Returns the namespace id (not the name) that the link points to
$link->to: Returns the article title (not the id and not including the namespace) that the link points to