Manual:Page ID

The page ID is of the page table. There is a magic word,, that displays the page ID. There are also many API features that either return the page ID or use it as an input. For example, https://www.mediawiki.org/w/api.php?action=query&prop=pageprops&titles=Manual:Page_ID will show that this is page. Page IDs do not change when pages are moved, but they do change when pages are deleted and then restored.