The WHOIS information of a domain is a collection of various details that are publicly accessed via specific lookup sites or a command line. The protocol which makes this possible bears the same name and you could very easily see the company where a domain name has been registered, the creation, expiration and last update dates together with the names, postal and e-mail address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain. All this info ought to be valid and up-to-date at all times; otherwise 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 ensure that the WHOIS details of your domain names are legitimate. Updating the WHOIS for a variety of country-code TLDs is limited, so whenever you register a brand new domain address, it is best to double-check the info you are submitting.