Definition: referrer

The URL of the Web page a request is coming from. When a link is clicked to go to another page, or when the Web page itself calls for an image to be displayed, the browser sends the URL of the current Web page along with the request.

On a search site, in addition to the URL, the text you are searching for is often sent to an advertising agency that sends back a tailored banner ad or just collects demographics. Most ad blocker programs can eliminate referrer data. See ad blocker.

Blocking Referrer Data

The interMute program was an example of a utility that could keep referrer data from being transmitted.