The WHOIS info of a domain name is a collection of many details that are openly accessed via special lookup Internet sites or a command line. The protocol which makes this possible carries the same name and you could very easily see the organization through which a 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 specific domain address. This info ought to be correct and up-to-date constantly; otherwise the domain registration may be challenged. The latter is a policy of ICANN (the Internet Corporation for Assigned Names and Numbers), this means you should always make sure that the WHOIS details of your domains are accurate. Updating the WHOIS for a variety of country-code TLDs is limited, so any time you register a completely new domain, it is best to double-check the information that you're submitting.