what http request header is used to denote what uri linked to the resource being requested?
The HTTP request header you’re looking for is the Referer header. In plain
terms:
Refereris the header that tells the server which URI (page) linked to the resource being requested.
So if page A at https://example.com/page.html includes an image from
https://cdn.example.com/img.png, when the browser requests img.png, it
will typically send:
http
GET /img.png HTTP/1.1
Host: cdn.example.com
Referer: https://example.com/page.html
That Referer value is the URI of the document that contained the link to the
requested resource.
