A fully qualified domain name (FQDN) is the complete domain name for a specific computer, or host, on the Internet.
The FQDN consists of two parts: the hostname and the domain name.
For example, an FQDN for a hypothetical mail server might be
The hostname is
mymail, and the host is located within the domain
A FQDN is divided in three levels:
1) The appendage of the domain is the Top Level Domain (TLD). Example: net, com or eu
2) The domain name will be inserted in front of the TLD. Example: openemm or agnitas
3) At the very first stands the hostname. For webpages mostly: www
The FQDN www.yourcompany.com is composed of:
– www = hostname
– yourcompany = domain name
– com = TLD
As you can see, the FQDN consists of the hostname, the domain and the top level domain separated by dots. Finally the server IP address (i.e. 172.16.13.52) will be replaced by the addressable www.yourcompany.com address.
The FQDN can be expanded with a subdomain (i.e. miami). The subdomain will be inserted between the hostname and the domain name. Example: