The WHOIS info of a domain name is a collection of various details which are openly accessed using specific lookup websites or a command line. The protocol which makes this possible carries the same name and you may effortlessly see the firm through which a domain name has been registered, the creation, expiration and last update dates in addition to the names, postal and email address of the people listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain name. All this info ought to be valid and up-to-date at all times; if it's not the domain name registration can 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 domain addresses are legitimate. Updating the WHOIS for a number of country-code TLDs is limited, so whenever you register a completely new Internet domain, it is best to double-check the info that you are submitting.