A 301 redirect is a page status code that tells search engines a page has permanently moved to another URL. The new URL might be on the same site or on a different one. You use a 301 redirect when you want to capture the traffic to the old address but the page is now physically elsewhere. For instance, if you change filenames, this usually leads to changes in the URL of the page and if you don’t do a 301 redirect, when visitors come to your old URL, they will see a Page Not Found message. There are many ways to perform a redirect and your options are limited by the technology (i.e. PHP, ASP, etc.) you are using. If you want to check if your URLs are redirecting properly, use the Redirect Check tool.