The WHOIS info of a domain name is a collection of various details which are publicly accessed using specific lookup Internet sites or a command line. The protocol which makes this possible has the same name and you could very easily see the firm 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 Internet domain. This information should be valid and up-to-date at all times; 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 several country-code TLDs is limited, so any time you register a new domain name, you ought to double-check the information you are submitting.