What is WHOIS?
In Summary:
WHOIS is both a directory and a protocol. WHOIS directories are used to obtain information about networks, networking organizations, domains, sites, and the people associated with them. The WHOIS protocol describes the application used to access these directories.
WHOIS generally provides personal name, organization name, postal address, e-mail
address and phone number for people associated with networks; and domain names and IP
addresses for networks themselves.