The FQDN is the full name of a system, rather than just its hostname. For example, "venera" is a hostname and "venera.isi.edu" is an FQDN. See also: hostname, Domain Name System. [Source: RFC1392
Abbreviated to FQDN, the complete domain name by which a network resource can be accessed. Usually in the format of "host name.domain name.domain root". Although the FQDN can also extend down several tiers of the domain name space to incorporate second level and child domain names.
A domain name ending with a dot (.).