WHOIS works through a protocol that provides a standardized way to query information about a registered domain name and its owner. When someone performs a WHOIS search, the search request is sent to a WHOIS database, which is maintained by an organization such as ICANN (Internet Corporation for Assigned Names and Numbers). The WHOIS database contains information about all registered domain names and their owners, which are provided by domain registrars.

The information available through WHOIS can vary depending on the domain name and registry. However, the WHOIS information typically includes the domain name, creation and expiration dates, the registrar used to register the domain, and contact information for the domain owner, administrative contact, and technical contact.

Some domain registrars offer the option to hide or anonymize the WHOIS information for a domain. This can be done through the use of a privacy service, which displays the contact information of the privacy service instead of the actual contact information of the domain owner. This protects the owner's privacy and helps prevent spam and unwanted communication.