A plain-language explanation
Orphan Pages are subpages without internal links leading to them from other available parts of the website.
Where it helps in practice
An orphan page lacks a meaningful route from other pages, making it hard for users and crawlers to discover despite a sitemap entry.
The decision before implementation
Decide whether to retain and link, merge, redirect or remove the URL.
How to verify the result
Compare crawls, logs, sitemaps, traffic and backlinks before applying an automated rule.