The WHOIS info of an domain is a collection of numerous details which are openly accessed using specific lookup sites or a command line. The protocol that makes this possible bears the same name and you may very easily see the organization through which an Internet domain has been registered, the creation, expiration and last update dates together with the names, postal and email address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain address. All of this info has to be legitimate and up-to-date all the time; if it's not the domain registration may be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), this means you should always ensure that the WHOIS details of your domain addresses are accurate. Updating the WHOIS for a variety of country-code TLDs is limited, so any time you register a brand new Internet domain, make sure you double-check the info you're submitting.