whois

(pronounced: who-is)

A Web-based utility used to look up names in a remote database, it was initially used as an aid for finding the e-mail addresses of people in large institutions or companies. Now it is primarily used to look up domain name ownership information on InterNIC, the organization that maintains it. As such, it is a searchable database that contains information about networks, networking organizations, domain names, and the contacts associated with each, for the .com, .org, .net, .edu, .mil, and "ISO 3166" country code top-level domains.

Whois also refers to the protocol, or set of rules, that describes the application used to access the database. Other organizations have implemented the whois protocol and maintain separate and distinct whois databases for their respective domains.