The WHOIS information of a domain name is a collection of a variety of details which are publicly accessed through special lookup Internet sites or a command line. The protocol that makes this possible has the same name and you can very easily see the organization 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 particular domain name. All of this info ought to be correct and up-to-date constantly; otherwise the domain name registration can be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), so you must always make sure that the WHOIS details of your domain addresses are valid. Updating the WHOIS for a variety of country-code TLDs is limited, so any time you register a brand new domain name, you ought to double-check the info that you're submitting.