The Free On-line Dictionary of Computing (30 December 2018):
URL redirection
URL forwarding
    (Or "URL forwarding")
   When a web server tells the client browser to obtain a
   certain requested page from a different location.  This is
   controlled by directives in the server's configuration files
   or a "Location: header output by a CGI script.
   The web server stores all its documents in a directory tree
   rooted at some configured directory, known as its "document
   root".  Normally the URI part of the URL (the part after
   the hostname) is used as a relative path from the document
   root to the desired file or directory.  A redirect directive
   allows the server administrator to specify exceptions to this
   general mapping from URL to file name by telling the browser
   "try this URL instead".  The new URL may be on the same server
   or a different one and may itself be subject to redirection.
   The user is normally unaware of this process except that it
   may introduce extra delay while the browser sends the new
   request and the browser will usually display the new URL
   rather than the one the user originally requested.
   (1997-07-15)