View source for FQDN

A fully qualified domain name (FQDN)is a domain name that specifies its exact location in the tree hierarchy of the Domain Name System (DNS).  It consists of a host and domain name, including top-level domain.  It specifies all domain levels, including the top-level domain and the root zone. A fully qualified domain name is distinguished by its lack of ambiguity: it can be interpreted only one way.

  host.domain.com

# host = the first part of the FQDN is the hostname which can be www as an example.  This is sometimes an alias called a cname.
# domain = domain name hierarchy word
# com = This is the TLD or top-level domain.  Common examples are the original .com .net and .org.