The WHOIS info of a domain name is a collection of numerous details which are openly accessed using specific lookup sites or a command line. The protocol which makes this possible bears the same name and you can effortlessly see the firm through which a domain name 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 Internet domain. This info should be legitimate and up-to-date all the time; 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), so you must always make sure that the WHOIS details of your domain addresses are legitimate. Updating the WHOIS for a number of country-code TLDs is limited, so when you register a new domain address, make sure you double-check the information that you are submitting.