a.k.a. refer field
The URL of a Web page that refers users to your Web site. When you're an indie developer, it's a good thing. In the online advertising arena, it has a much different meaning: A referrer is information passed along to ad networks (or other marketers) as a user sends e-mail, searches on a search engine, or navigates from one site to another. Referrers in this sense are used in creating online profiles that make it possible to target online ads.
NetLingo Classification: Online Business