The WHOIS service provides a way of finding e-mail addresses, postal addresses and telephone numbers of network users. It may also deliver information about networks, networking organizations, domains and sites. This service was originally called NICNAME, but WHOIS is now the name in widest use.

The Internet Registration Service maintains an important database of networking information, the InterNIC database. The names of the administrative and technical contacts for registered domains are automatically entered into the database when domain or IP number applications are processed by the Internet coordination authority.

After issuing a WHOIS query, the server searches the database an entry which contains the identifier being queried. This WHOIS utility queries only on site-name. A site name is the domain address of the site which hosts the database you want to query (e.g. sambar.com).