When running the web interface, your transactions are passed from your web browser to a web server. The web server starts up a CGI (Common Gateway Interface) program which interfaces with the Cyc Server: a machine running the Cyc software which has loaded some version of the Cyc KB. These may all be running on the same machine, but the web browser, Cyc server, and web server/CGI program could be running on three different machines.
There may be several machines functioning as Cyc servers. In the simplest setup, each of these machines also has its own web server (this is also the fastest setup, since the connection between the web server and the Cyc server does not use the network). Assuming that this is your setup, and the machine you want to use is "host.domain.com", then you start by opening the URL: