The WHOIS information of a domain name is a collection of a variety of details which are publicly accessed using special lookup websites or a command line. The protocol that makes this possible bears the same name and you can easily see the organization through which a domain has been registered, the creation, expiration and last update dates in addition to the names, postal and email address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a specific domain name. All this information has to be legitimate and up-to-date constantly; otherwise the domain name registration could be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), this means you should always make sure that the WHOIS details of your domains are legitimate. Updating the WHOIS for a variety of country-code TLDs is limited, so any time you register a new domain address, you should double-check the information you're submitting.