Canonical name
(CNAME) A host's official name as opposed to an alias.
The official name is the first hostname listed for its
Internet address in the hostname database, /etc/hosts or the
Network Information Service (NIS) map hosts.byaddr ("hosts" for short).
A host with multiple network interfaces may have more than one Internet address, each with its own canonical name (and zero or more aliases).
You can find a host's canonical name using
nslookup if you say
set querytype=CNAME
and then type a hostname.
