The WHOIS info of a domain name is a collection of a variety of details that are freely accessed via special lookup sites or a command line. The protocol which makes this possible carries 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 together with the names, postal and email address of the individuals listed as Registrant (owner), Administrative, Technical and Billing contacts for a specific domain name. All this information must be legitimate and up-to-date all the time; 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), therefore you should always make sure that the WHOIS details of your domain names are legitimate. Updating the WHOIS for a variety of country-code TLDs is limited, so when you register a completely new domain, you should double-check the information you're submitting.