Orphan Pages
Pages that exist on a website but have no internal links pointing to them, making them harder for users and crawlers to discover.
Orphan pages are URLs that exist on a website but are not linked from any other crawlable internal page. They may appear in an XML sitemap, analytics report, CMS export, or server log, but a crawler following normal internal links would not discover them.
From an SEO perspective, orphan pages are risky because they receive little or no internal PageRank, provide weak site-architecture signals, and can be crawled or indexed inconsistently. Important orphan pages often underperform because search engines see fewer internal signals proving that the page matters.
The usual fix is not simply adding every orphan to the footer. Add contextual internal links from relevant hub pages, category pages, articles, or navigation paths; remove stale orphan URLs that no longer deserve indexation; and keep the XML sitemap aligned with pages you actually want crawled and ranked.