Hostname

In computer networking, a hostname (archaically nodename) is a label that is assigned to a device connected to a computer network and that is used to identify the device in various forms of electronic communication, such as the World Wide Web. Hostnames may be simple names consisting of a single word or phrase, or they may be structured.

On the Internet, hostnames may have appended the name of a Domain Name System (DNS) domain, separated from the host-specific label by a period ("dot"). In the latter form, a hostname is also called a domain name. If the domain name is completely specified, including a top-level domain of the Internet, then the hostname is said to be a fully qualified domain name (FQDN). Hostnames that include DNS domains are often stored in the Domain Name System together with the IP addresses of the host they represent for the purpose of mapping the hostname to an address, or the reverse process.

Hostnames are human-readable nicknames that correspond to the address of a device connected to a network. They are used by various naming systems, e.g., Network Information Service (NIS), Domain Name System (DNS), Server Message Block (SMB) and the meaning of hostname varies according to the naming system used. A hostname meaningful to a Microsoft NetBIOS workgroup may be an invalid Internet hostname.

Hostnames are typically used in an administrative capacity and may appear in computer browser lists, active directory lists, IP address to hostname resolutions, email headers, etc.

Saturn and jupiter may be the hostnames of two devices connected to a network named Example. Within Example, the devices are addressed by their hostnames. The domain names of the devices would be saturn.example and jupiter.example, respectively. If 'example' is registered as a second-level domain name in the Internet, e.g. example.net, the hosts may be addressed by the fully qualified domain names saturn.example.net and jupiter.example.net.

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