Telling search engines what exists.
WHAT A SITEMAP IS
A file listing your pages, helping engines find them. It does not guarantee indexing but it helps discovery, particularly for new pages and large sites.
GENERATING ONE
Most content systems produce one automatically, or via an SEO plugin. It is usually at /sitemap.xml or /sitemap_index.xml.
Check yours exists by visiting the URL.
SUBMITTING IT
Search Console > Sitemaps. Enter the path and submit.
WHAT IT SHOULD CONTAIN
Pages you want indexed, with their canonical URLs, using https.
WHAT IT SHOULD NOT CONTAIN
Pages set to noindex Redirected URLs 404s Duplicate versions Admin or utility URLs
A sitemap full of errors reduces trust in it.
MAINTAINING IT
Automatically generated sitemaps update themselves. Check occasionally that the count is plausible and that Search Console reports no errors.
AFTER A MIGRATION
Regenerate and resubmit. A sitemap listing your old URLs after a domain or protocol change is actively unhelpful.