The WHOIS information of a domain is a collection of a number of details that are openly accessed through special lookup sites or a command line. The protocol which makes this possible has the same name and you may very easily see the company through which a domain name has been registered, the creation, expiration and last update dates as well as the names, postal and email address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain name. All this information should be correct and up-to-date constantly; if it's not the Internet domain registration may be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), this means you must always make certain that the WHOIS details of your domain addresses are valid. Updating the WHOIS for numerous country-code TLDs is limited, so when you register a new domain address, you ought to double-check the info that you're submitting.