301 Moved Permanently
Meaning
The requested resource has been assigned a new permanent URI, and any future references to this resource should use one of the returned URIs.
When to Use
When a resource has been permanently moved to a new URL and the client should use the new URL for all future requests.
Example
A GET request to an old endpoint returns 301 Moved Permanently with a Location header pointing to the resource's new permanent URL.
When Not to Use
Do not use for temporary relocations (use 302 or 307 instead) or when the move is not permanent.
Source
RFC 9110