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