On a Web site, redirection is a technique for moving visitors to a different Web page than the one they request, usually because the page requested is unavailable. Web users often encounter redirection when they visit the Web site of a company whose name has been changed or which has been acquired by another company.
In either case, the Web site probably will include a new domain name and it will have a new Uniform Resource Locator (URL). To make sure that visitors familiar with the old company get to the new site, the company will turn the original Web site home page into a redirect page, containing a message 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."
In addition to replacing the content of the old page with the redirect text, the company adds a meta refresh line in the header section of the page that looks something 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.
Redirection is also conducted illegally by browser hijackers that surreptitiously change the user's browser settings.