A WHOIS query is a way to obtain information about a domain name, including the owner's name, the location the domain is registered, when the domain expires and what nameservers the domain is using. WHOIS searches can locate a Web administrator's contact information when none is listed on a website.

Many domain registrars offer private registration services. This allows an individual, a business or an organization to prevent contact information from being listed in WHOIS queries for the domain. Using private registration results in the details of a proxy being shown in the domain's WHOIS information rather than that of the person or group that registered the domain.