Sitemap.xml
The sitemap.xml is a file listing all the important pages of a site, to help search engines discover and crawl them.
On a small site, search engines find pages without help. On a larger or newer site, the sitemap speeds up discovery and signals updates.
A clean sitemap, submitted through Search Console, contains only valid, indexable pages. Leaving broken or redirected pages in it muddies the signal sent to search engines.