The WHOIS information of a domain is a collection of many details that are freely accessed using special lookup websites or a command line. The protocol that makes this possible bears the same name and you can easily see the firm where a domain address has been registered, the creation, expiration and last update dates along with the names, postal and e-mail address of those listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular Internet domain. This information ought to be valid and up-to-date constantly; if it's not the domain name registration could be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), so you should always make certain that the WHOIS details of your domains are valid. Updating the WHOIS for several country-code TLDs is limited, so any time you register a new domain name, it is best to double-check the information you're submitting.