Internet Protocol address. A number analagous to a street address on the Web. See IP Number. When the internet was invented many years ago, there needed to be a way to identify one computer from another. The "IP" or "internet protocol" address has been used since then. In fact many corporate networks assign IPs to desktop computers without the employee knowing that they've been using Internet related technology for years, whether connected to the internet or not. When a Web server is setup, it has its own IP address to identify itself on the local network. Each virtual server is given its own static (non-changing) IP address as if it were its own machine.