The WHOIS information of a domain name is a collection of many details that are publicly accessed via specific lookup websites or a command line. The protocol that makes this possible bears the same name and you can very easily see the company through which an Internet domain has been registered, the creation, expiration and last update dates in addition to the names, postal and email address of the people listed as Registrant (owner), Administrative, Technical and Billing contacts for a particular domain address. This info should be valid and up-to-date all the time; otherwise the Internet domain registration could be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), this means you should always make certain that the WHOIS details of your domain addresses are accurate. Updating the WHOIS for several country-code TLDs is limited, so any time you register a brand new Internet domain, make sure you double-check the info that you're submitting.