Answers for "What HTTP Status Code does a server use to indicate to a client, that the resource they have requested has been permanently moved to a new URL ?"

200 error code

The HTTP 200 OK success status response code indicates that the request has succeeded. A 200 response is cacheable by default. The meaning of a success depends on the HTTP request method: GET : The resource has been fetched and is transmitted in the message body.

from developer.mozilla.org