On a Web site, a meta refresh is coding in the Hypertext Markup Language (HTML) that automatically directs the visitor to a new page after a specified number of seconds. It's used when the address of a page is changed but you want visitors who know the old address to be able to find the new page. The page containing the meta refresh tag is known as a redirect page and the technique is known as redirection.
Most Web surfers are familiar with the meta refresh. A user enters a Uniform Resource Locator on their browser's address line and it takes them to a page that says something like: "We have moved to a new location. Please change your bookmark. In five seconds, we will transfer you to the new page." To make the transfer happen in five seconds, someone at that site has included an HTML line in the header section of the old page that looks like this:
<meta http-equiv="refresh" content="5;url=http://www.ournewsite.com">
In the above example, the "5" means change to the new page in five seconds. The "url=http://www.ournewsite.com" is an example of the URL for the new page.
If you own a Web site that people have learned to use and you then change the name and location of a Web page, it's strongly recommended that you make the original page a redirect page with a meta refresh tag to the new page. Otherwise, visitors familiar with the old page will get a 404 (Page Not Found) message.