Referrer String
 

Referrer String - A piece of information sent by a user’s browser when they navigate from page to page on the web. It includes information on where they came from previously, which helps webmasters understand how users are finding their website.

Referrer string is the value assigned to each URL in a set of search results.

This is an Header field that define the address of the webpage that linked to the resources being requested.

Thanks Alka! for sharing this post with us, this is really informative post.:)