HTTP:Headers:Referer
lastmod 2023-08-20created 2023-08-201 edits
A referrer is the trace left when, while surfing the World Wide Web with a web browser, you visit each site through a hyperlink.
For example, suppose web page A has a hyperlink to site B. When a website user clicks this hyperlink, the web browser sends the referring address (the referrer) to site B. The administrator of site B can see this referrer and learn that the visitor came to their site through site A.
It is useful when a website's server administrator wants to find out by what route visitors came to the site. However, since referrers can also be forged, you should always be careful about security when using referrer information.
In short, information that shows which site the visitor came from
referrer vs referer
The HTTP referrer is called 'HTTP referer' because the RFC that defined it misspelled 'referrer' as 'referer'.