The whois service supplies information on the owners of IP addresses and domain names. Enter a name, such as h-online.com or an IP address, such as 18.104.22.168.
If you enter an IP address and do not receive any meaningful information, the IP address may be a reserved address.
The output may include references to further information in the form of 'handles' e.g. HHH40-RIPE. You can also query records of this type here.
The whois program goes from server to server using the RFC 3912 whois protocol until it finds the registrar responsible. It then fetches the information required from that registrar's database.