Many people don't realize that browsers cache 301 redirects. A 301 redirect is a permanent redirect from one URL to another. It only makes sense that a browser should cache a 301 redirect, after all, it is permanent.
Determining whether to use www in your canonical URLs is an important decision and should be reinforced by redirects to prevent duplicate content from an SEO perspective. Definition of a WWW Redirect A www redirect is a rule on your web server that forwards all traffic from the non-www version of your domain to the … Continue reading WWW Redirects with .htaccess
Anytime you migrate a web site, or even just relocate a single page to a new URL, redirects ensure that your users don't get lost in the shuffle. Search engines also use redirects to aid in properly indexing your site's content.