We generally see the term FQDN or
Fully Qualified Domain Name and generally, though that is is like secret magic that provides some information about the servers and hosts. No. The answer is no the FQDN provides no secret or magic. We use FQDN in order to specify hostnames in a hierarchical manner. Below we will look at how we calculate FQDN.
The hostname is used to identify hosts with meaning full names. For example, when we set up the Windows operating system the Windows set the hostname of the computer with the created user name like IsmailPC. Of course, we can change this hostname whatever we want. The following list provides an example of hostnames.
Production1 LabPC Poftut2 Home www
A domain name is used to create a domain with a name. The Internet provides a consistent and unique domain name hierarchy. For example, poftut.com specifies this site which is a domain name. We can use domain names not just sites also other things like databases, services, etc.
FQDN = Host Name + Domain Name
Now we came to the real topic. We have learned the basics which creates FQDN. Fully qualified means the whole and domain name cames after that. Fully qualified domain name consist of
Host name + Domain name . FQDN specifies the host whit out any extra description. For example:
www.poftut.com specifies the host which provides
www or web services.
Automatic WWW Host name
Normally while surfing the internet we can type URL as poftut.com. This is not a fully qualified domain name even does not provide the hostname. But the browser automatically add www as default as it expects from us to surf in
poftut.com web site.
Partially Qualified Domain Name
Hostnames can be named as Partially Qualified Domain Names. Because hostnames do not provide the domain name. We can only use the hostname if we know or automatically add the domain name to the hostname. For example, if we are in the same domain we can use PQDN for communication and specification.