A 301 redirect is a method of telling web browsers and search engines that a website or web page has permanently moved to a new location or address. An example of this might be:
A webmaster wants to change their domain URL from www.domain.co.uk to www.domain.com. By adding a 301 redirect from the .co.uk address to the .com address, a web visitor using a standard web browser will automatically be re-directed to the .com address. Additionally, a search engine will also automatically be redirected to the new domain. Because a 301 redirect indicates a permanent change of address, the search engine should also automatically update all the links within it’s index. Also, any search engine page rankings and links to the site should also be preserved which is very important, especially for older, more established websites.
301 redirects are also used internally for websites to prevent internal content duplication issues such as canonicalization / canonicalisation and for updating page names. For example, if an unfriendly URL is changed so that is ‘friendly’ a 301 redirect would be used from the old link to the new so that users and search engines know the location has permanently changed i.e.
Changing www.domain.com/page?124 to www.domain.com/services.
