FQDN: What Is a Fully Qualified Domain Name + Real-Life Examples

Key takeaways:

• FQDNs offer convenience and organization benefits.
• FQDNs are complete and specific address of a server.
• FQDNs help clearly identify resources on the internet without confusion.

A key part of leveraging the internet for brand marketing is domain names, which serve as an address for websites online. Fully qualified domain names (FQDN) stand out as a cornerstone of internet navigation and website identity.

This guide aims to demystify FQDNs, offering insights into their role, significance, and how they differ from their counterpart, the partially qualified domain name (PQDN).

What is a fully qualified domain name?

A fully qualified domain name (FQDN), also known as an absolute domain name, is the complete and specific address of a server or host on the internet. Think of it as the full mailing address of an online location. Just as your home address includes your house number, street, city, and zip code, an FQDN encompasses every part of the domain, ensuring an exact and unique destination.

For instance, in the FQDN “mail.example.com,” “mail” is a subdomain of “example.com,” forming a complete path to the specific mail server under the “example.com” domain.

What are the elements of an FQDN?

An FQDN is a complete domain name that includes:

• A top-level domain
• A second-level domain
• A subdomain
• A hostname

Top-level domain

The top-level domain, also known as TLD, is the last part of a complete domain name. It comes after the dot (.).

For example, in www.blog.example.com, .com is the TLD. Other examples of TLDs are:

• .org
• .net
• .shop

Second-level domain

The second-level domain sits directly before the TLD. It’s usually the name of the business or organization that owns the domain.

In the example www.blog.example.com, example is the second-level domain.

Subdomain

The subdomain comes before the second-level domain. So, in www.blog.example.com, blog is the subdomain.

Subdomains help divide the main website into sections, pointing to specific pages of a website.

Hostname

Hostnames appear in the leftmost part of the FQDN. You’ll see it after the http:// or https:// of a web address. It identifies the server connected to a network.

For example:

• www for web servers 
• mail for mail servers 
• ftp for file transfer servers

How an FQDN works

Each time you search online, your device sends and receives packets of data accross different servers. It’s a fast process.

To achieve this, every web server or device is given a corresponding IP address, a set of numbers that lets your device interact with others. Why? Because computers don’t process words, they rely on numerical data.

When you enter a domain like NetworkSolutions.com, your web server checks to see if any records for Network Solutions are already in your cache. If not, it directs your query elsewhere.

This is where the Domain Name System (DNS) play its part. The DNS records Fully Qualified Domain Names together with their corresponding IP addresses. This allows computers to communicate efficiently and quickly identify a site’s IP address, while users can base on human-readable domain names.

Instead of typing a complex string like 172.64.145.59, you can enter the FDQN into a web browser, and the DNS will handle the lookup for you.

Examples of FQDN in real life

A well thought-out and organized FQDN can bring benefits like improved security and brand cohesion. 

Here are some more examples to illustrate their structure and diversity:

Web server example

FQDN example: www.example.com

In this instance, www is the subdomain, example is the second-level domain, and .com is the top-level domain (TLD). This FQDN points to the main web server of the example.com domain.

Mail server

FQDN example: mail.company.org

Here, mail is the subdomain typically used for email servers, company is the second-level domain, and .org is the TLD. This FQDN is important to access the email server of company.org.

FTP server

FQDN example: ftp.archive.net

For this illustration, ftp indicates a subdomain used for a file transfer protocol (FTP) server, archive is the second-level domain, and .net is the TLD. One would use this FQDN for file transfers associated with archive.net.

Database server

FQDN example: db1.internal.example.com

In this case, db1 is a subdomain representing a specific database server. Internal is a secondary subdomain indicating an internal network. Then, example.com forms the main domain. A company uses this FQDN to access a particular database server.

API server

FQDN example: api.service.example.co.uk

Here, api signifies a subdomain for an Application Programming Interface (API) server, service is the second-level domain, and example.co.uk is the main domain with a country-specific TLD. This FQDN points to an API server for service.example.co.uk.

Cloud service

FQDN example: cloud-storage.enterprise.com

In this instance, cloud-storage is a descriptive subdomain, enterprise is the second-level domain, and .com is the TLD. This FQDN could lead to a cloud storage service for enterprise.com.

Educational institution

FQDN example: student.portal.university.edu

Here, student is a subdomain, portal is the secondary subdomain for a student portal, and university.edu is the main domain with an educational TLD.

Government website

FQDN example: services.department.gov.us

This example shows that services is a subdomain for a specific service, department is the second-level domain, and gov.us indicates a government domain in the United States. This FQDN might point to a particular service offered by a government department.

How FQDN is different from PQDN

Partially qualified domain names (PQDN) represent only a portion of a full domain name, often omitting certain elements like subdomains or the top-level domain (TLD). For instance, using just “example” instead of the full “www.example.com” is a PQDN.

While PQDNs can be convenient within certain closed networks or specific contexts, they lack the universality and specificity of FQDNs, which might lead to ambiguities in the broader internet environment.

Technical insights: FQDN vs. PQDN

FQDNs are key for a globally unambiguous identification of internet resources, ensuring each address leads to a unique location. PQDNs, while useful in localized settings, might result in confusion or misdirection when used in a broader context. For businesses seeking a robust online presence, FQDNs offer the reliability and specificity needed for effective digital operations.

What are the benefits of using FQDNs?

FQDNs offer numerous benefits, notably in terms of convenience and organization. They are easier to remember and use than numerical IP addresses, providing a user-friendly way to access websites.

Additionally, FQDNs allow for clear segregation of different services under one domain, like differentiating “shop.example.com” from “blog.example.com.” This segmentation enhances the user experience by directing them to the appropriate service.

Here are other benefits of using FQDNs.

To get SSL certificates

FQDNs play a role in secure sockets layer (SSL) certificates. Certificate authorities (CAs) issue these certificates, which secure and encrypt data between a user and a website, to websites with a valid FQDN. This requirement underscores the importance of FQDNs in establishing secure, trustworthy online interactions, which are a must-have for any eCommerce or data-sensitive website.

To optimize your website

Proper use of FQDNs can indirectly enhance your website’s effectiveness and SEO performance. By choosing a clear, descriptive FQDN, you make your site more accessible and memorable to your audience.

How to find an FQDN

FQDNs aren’t limited to websites only. Your device also has its full name. To locate them, here’s how:

For Windows users 

1. On the Start menu, search and click View your PC name.
2. In the Related links row, click Advanced system settings.

You’ll see FQDN in the Full Computer Name field.

For macOS users

1. Navigate the Apple menu and click Settings.
2. Click Sharing
3. Scroll down to the Local hostname section to see your FQDN.

For Linux users

1. Press CTRL + ALT + T to open the Terminal app.
2. Enter hostname –fqdn

Using FQDN for digital success

Understanding and utilizing FQDNs is beyond being a technical requirement; it’s a strategic step toward establishing a strong, recognizable online presence. As we’ve explored, the benefits of FQDNs range from improved navigation and organization to enhanced security.

With its comprehensive suite of digital solutions, Network Solutions is ready to assist you in navigating this aspect of your journey to success. Use our domain name search tool to find the perfect domain name for your brand!

Frequently asked questions