Try to refresh this page several times, reopen the tab, reopen the browser and finally, open it in Private (Incognito) mode.
HTTP Cookie is a key-value pair set by the Web server and transmitted to the browser in the form of HTTP response header.
HTTP Etag is a token of a specific version of the resource and set by the Web server in the form of HTTP response header.
HTTP 301 Moved Permanently is a redirection instruction set by the Web server in the form of HTTP response.
HTTP Last-Modified is a timestamp of the resource set by the Web server in the form of HTTP response header. Since 01-01-101 may hold 60.5 billion uniques.
The demonstration may set pseudo-random online identifier. But don't worry! The identifier is not shared, used solely for this demo and will be removed in 5 minutes automatically.