The feature is very useful if you have recently redesigned your site but you wish to keep
the old addresses working for various reasons (you have links to these pages from other
sites, some users may have the old pages bookmarked, etc).
The Apache web server provides several way for setting up redirects.
The most simple one is using the Redirect directive:
Redirect /folder http://www.example.com/newfolder
With such a line in your .htaccess if a visitor tries to load
http://www.example.com/folder, he will be redirected to http://www.example.com/newfolder.
Recently it has been talked a lot about Permanent redirects. The good news is that you can
add a status code to the Redirect directive. For example for Permanent 301 redirect you can
use:
Redirect permanent /folder http://www.example.com/newfolder
Another useful directive is the RedirectMatch. With it you can use regular expressions in
the redirect condition. For example
RedirectMatch ".html$" http://www.example.com/index.php
This will redirect all requests to files that end with .html to the index.php file.
There is another more powerful way to create redirects or even create transperant redirects
which requires ModRewrite. Please refer to the articles on mod_rewrite.