Specifying the browser to automatically switch to another address after the specified number of seconds. If the url parameter is not specified, refresh the page without using the cache. Because of massive abuse to transfer users to an unsolicited resource, outright fraud and the use of this feature in the distribution of malicious software, almost all modern browsers ignore the instructions specified in the body of the page by default. In modern browsers, including mobile browsers, there are more sophisticated tools for updating data on the page: AJAX , Push Notifications , WebSockets , Web Workers , ....
For today - it is hardly applicable, practically meaningless and costly, both for the client, and for the server.
< meta http-equiv = "refresh" content = "5; url = http: //www.example.com/" />
<! - After url = no quotes! ->