A fully qualified domain name (FQDN) is one that names both the host name and the domain name. Www.blurtit.com is an FQDN - www is the host name and blurtit.com is the domain name. If blurtit operated an FTP site it might be named ftp.blurtit.com - ftp would be the host name.
I think you must be looking for the description of a "partially qualified domain name" (PQDN) as FQDNs are what the public uses.
A PQDN is one that you could use if you were on the internal network of given site. For example, you are hired by blurtit to be a system administrator. When you come in to the office and pull up your browser you should be able to access their web site by simply typing "www" - just the host name. If your computer was configured correctly (of course it would be) then it would assume "blurtit.com" for the domain name and would take you to www.blurtit.com.
I think you must be looking for the description of a "partially qualified domain name" (PQDN) as FQDNs are what the public uses.
A PQDN is one that you could use if you were on the internal network of given site. For example, you are hired by blurtit to be a system administrator. When you come in to the office and pull up your browser you should be able to access their web site by simply typing "www" - just the host name. If your computer was configured correctly (of course it would be) then it would assume "blurtit.com" for the domain name and would take you to www.blurtit.com.
