Definition
WHOIS is a query/response protocol for looking up information about domain registrations. A WHOIS record shows: registrar, registration date, expiry date, nameservers, and registrant contact (if not privacy-protected). Most domains now use WHOIS privacy/proxy services hiding the real owner's contact info. WHOIS data is stored by registrars and accessible via whois.iana.org or domain registrars.
Use the tool: WHOIS Lookup — check whois for any domain.