Where are web server redirects used?
Web server redirects are used to redirect visitors to the right web page. They are often used during maintenance work, for instance in order to refer the visitor to an error page. But also with websites where one has to log in, a web server redirect is used to first redirect the visitor to the login page.
Web server redirects are also often used if a website is moving to a different domain name. A web server redirect (HTTP 301 with Moved Permanently) is placed on the old address to let the visitor, but also the search engine spiders, know that the website can be visited at a new address from now on. In the case of a HTTP 301 (permanent redirect), the old address of the website is also removed from the robot's administration.