The WHOIS information of a domain name is a collection of various details that are openly accessed using specific lookup sites or a command line. The protocol that makes this possible bears the same name and you could very easily see the firm where a domain name has been registered, the creation, expiration and last update dates in addition to the names, postal and e-mail address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain. All of this info should be legitimate and up-to-date at all times; if not the domain name registration could be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), therefore you should always ensure that the WHOIS details of your domains are valid. Updating the WHOIS for numerous country-code TLDs is limited, so whenever you register a brand new Internet domain, it is best to double-check the information you're submitting.