Manual:Page deletion

Page deletion occurs when a page is deleted by the action=delete parameter to index.php or by API:Delete. All of the revisions in the page are moved from the revision table to the archive table and the page entry is deleted. The page deletion system is entirely separate from the revision deletion system.

Page undeletion, or restoration, is done by Special:Undelete or API:Undelete. One or more revisions from the archive table are moved to the revision table and a new page entry, with a new is created. This entry's field will be set to 1.