An SEO problem.
WHAT HAPPENS
The same site reachable at several addresses.
Search engines see duplicate content and split ranking between them.
WHERE IT COMES FROM
Aliases serving the same content rather than redirecting The subdomain cPanel creates alongside an addon domain Both www and non-www resolving without a redirect A staging copy left indexed
HOW TO CHECK
Search for a distinctive phrase from your site.
If it appears at multiple addresses, you have duplicates.
HOW TO FIX IT
Choose one address as canonical Redirect all others to it permanently Block or password-protect staging copies
FOR WWW AND NON-WWW
Pick one. Redirect the other.
Both must resolve; then one redirects to the other.
FOR THE ADDON SUBDOMAIN
Redirect it to the real domain, or block it from indexing.
FOR STAGING
Directory Privacy, which prevents access and therefore indexing.
More reliable than a noindex tag.
