301 redirect tells you that a web page or media was moved permanently to a new address. Unlike 302 Redirect, 301 Redirect Moved Permanently HTTP status code signals search engines to update the links to the page in their indices.
For example, if you want to permanently move your website URL from “mydomain.com” to “myofficialdomain.com” you can do a 301 Redirect, and google or other search engines will change your URL in the search results too.