What is WHOIS
WHOIS is a protocol that is used to display information about domains, including the domain's registrar, domain creation and update dates, and contact information. WHOIS servers are usually operated by the five major regional Internet registries, or RIRs. Each RIR serves a major geographic region, such as a continent. In addition to the RIR WHOIS servers, some private databases exist. WHOIS information is available to anyone with Internet access with a WHOIS domain search. However, no specific purpose is set forth in RFC 3912 (WHOIS Protocol Specification).
WHOIS record information has become inherently useful to law enforcement agencies and Internet service providers (ISPs) in investigating complaints and alleged crime involving websites. While the information in a WHOIS record can be falsified, a number of steps have been put into place to aid in verifying the information. However, WHOIS information should usually not be treated as inherently accurate.
WHOIS information can also provide a level of assurance that a website is reliable, by providing information for making direct contact with the individuals or organization operating the website. Phone numbers, addresses, and other information found in a domain search can help to verify the website's identity.
One third and major purpose of WHOIS record information is useful to potential domain users. If a user is interested in purchasing a domain name, WHOIS records can be used to determine if that domain has already been registered. If it has, WHOIS records also give insight as to when the domain name might expire and be available again for registration.