What does FQDN mean?
Fully Qualified Domain Name is more commonly known as its short acronym FQDN. Its main purpose is to show specifically the most complete version of the name of a particular domain name. In addition, that could be related to a website or to a server.
The Domain Name System (DNS) is decentralized, and it has a very precise hierarchical order. The beginning and above everything else is the Root, and a level below is the Top-Level Domain (TLD). Next in the hierarchical order is the domain, and lastly is the precise hostname.
To make things a little bit more simple, here is an illustration of the full syntax of a Fully Qualified Domain Name (FQDN):
hostname. domain name. TLD
([hostname].[domain].[tld].)
Take note that oftentimes the dot “.” that is last is frequently neglected by regular users. It specifies the Root. However, it is not required when you are surfing the Internet on an everyday basis. There are only several cases when you are going to need it
Elements and Structure of FQDN
The Fully Qualified Domain Name (FQDN) actually has a very simple structure and three main elements. So, let’s explain a little bit more about them:
TLD (Top-Level Domain): It is illustrated with all of the familiar extensions that take place at the very end in an FQDN. Typically they are very short, and their length is only 2 or 3 letters, for instance, .com, .edu, .uk, etc. Of course, there are TLDs that are a little bit longer than that, such as .systems, .company, etc.
Domain: It is one level below the Top Level Domain (TLD) and is very familiar to everyday users. For illustration, website.com.
Hostname: It is easily defined with the symbols at the very beginning of the Fully Qualified Domain Name (FQDN). A very common and popular example is www in www.website.com. Depending on the need of the domain owner, he or she could make separate hostnames, and they are going to be connected to the domain. Here are some examples of such different hostnames:
- www.website.com
- ftp.website.com
- mail.website.com
Why do you need it?
There are so many different addresses on the Internet, and thanks to the FQDN, it is possible to describe the uniqueness of each of them. Therefore, it is crucial for a great online experience. Just imagine if there is no FQDN, your website is going to be hard to reach.
It is necessary to install an SSL certificate. This is because the majority of the websites are expected and required to have a feature like that.
Thanks to it, you have the ability to access domain services, such as File Transfer Protocol (FTP) and email. You are going to need it also if you desire to connect a domain name email to an email app.
What does PQDN mean?
A Fully Qualified Domain Name with a missing part is also known as a Partially Qualified Domain Name (PQDN). If there is a missing element, it won’t show the precise location on the DNS hierarchy. For illustration, website.com is a PQDN because it is missing the web host (www.) before the domain name. Regular users are used to typing only the PQDN because it is easier for them.