The WHOIS information of a domain name is a collection of numerous details which are freely accessed through specific lookup Internet sites or a command line. The protocol which makes this possible bears the same name and you could easily see the firm through which an Internet domain has been registered, the creation, expiration and last update dates together with the names, postal and email address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain. This info has to be legitimate and up-to-date at all times; if it's not the domain registration may be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), this means you should always ensure that the WHOIS details of your domains are accurate. Updating the WHOIS for numerous country-code TLDs is limited, so any time you register a new Internet domain, make sure you double-check the info that you are submitting.