The WHOIS info of an domain name is a collection of a variety of details that are freely accessed via special lookup Internet sites or a command line. The protocol that makes this possible bears the same name and you can easily see the organization where a domain name has been registered, the creation, expiration and last update dates along with the names, postal and email address of the individuals listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain address. This info must be valid and up-to-date all the time; otherwise the domain address registration can be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), so you must always ensure that the WHOIS details of your domain addresses are valid. Updating the WHOIS for a number of country-code TLDs is limited, so whenever you register a completely new domain name, you should double-check the info that you're submitting.