Hostname is the unique name of a computer in a network. A fully qualified host name is a hostname, either as a fully qualified name of a domain or IP address. During installation of a PHP MySQL based software, like WordPress, we often face this Hostname field, for the most we keep it as localhost, but for all guides on Rackspace, we mentioned the point to not type the Hostname as localhost but to use the specific MySQL server’s name like my-ep3.rt67.websitesettings.com, this one is not actually Hostname but more specifically a Fully Qualified Host Name. All computers are localhost like we refer ourselves as “I”, in case of a node, Fully Qualified Host Name is required as there are several physical computers.
What is Hostname
Historically, Hostname originated due to HTTP GET request to the file in /etc/hosts directory of the server. The host name of a physical system is the name under which the system itself is known.
For the computers that are directly connected to the Internet, typically uses a Fully Qualified Domain Name (FQDN) except the internal connections like using for MySQL database connection as said at the beginning. For the computers that forms a LAN, the domain part is usually omitted and only the local part is used.
Hostname versus Fully Qualified Host Name
Fully Qualified Host Name is a subnet and where the computer’s Hostname is ” my-ep3″ then a Fully Qualified Host Name the Fully Qualified Domain Name of this host will be like my-ep3.rt67.websitesettings.com or the IP address of the computer, such as 192.0.2.123. Now it became easier to you, why use mention and add a screenshot to change it the Hostname field from localhost to a bigger name – it is actually a Fully Qualified Host Name.