What is a Domain?

A web domain is an “address” on the web. In your web browser, if you type google.com, you will go to Google’s main, or “home” page. A domain name needs to be registered with a global organization (known as ICANN). You can register a domain with an ICANN-accredited domain registrar. You can usually register a domain when you purchase web hosting space, or you can register a domain separately (we use Reclaim Hosting for both of these). A domain name is unique and can only be registered to one organization or person at a time. You need to renew a domain annually or your will lose it.

We see web domains and their associated websites all the time – google.com, amazon.com, whitehouse.gov, hardvard.edu. A domain is actually made up of two parts – The domain name (or second-level domain) – google, amazon, whitehouse – and then the “top level domain” is the .com, .gov, and .edu endings. A domain is like a name in a phonebook or contact list. Associated with the name is a number and that number is how the computer networks talk to each other. Google’s “number”, or at least one of them, is 216.58.219.174 (Also try 216.58.192.46). Typing in that number in a web browser will get you to Google’s home page. However, it’s easier to remember google.com than it is to remember the number(s). This system is called DNS or Domain Name System. DNS uses a Domain Names System server, and that is a special computer server that acts as the “lookup” authority. Think of it as a global domain contact list. There are many local DNS servers that talk to other DNS servers and they are constantly talking to each other and updating their contact list. Below are a couple of real-world lookups.

Can I find the IP address of my domain?

You would need to use what’s known as a Terminal program (or terminal emulator). A terminal is a text-based interface that gives you access to a computer, either your own or another computer on the network. You type in text commands at a command line or “prompt”.

To find an IP address, you start the Terminal and type the following:

ping google.com

After you hit the Enter key, you would get a streaming set of data repeated until you hit the Ctrl-c key combination. Google’s IP address may change because they’ve got lots of servers.

What is UNF’s IP address?

Let’s try something more familiar. In the terminal type:

ping www.unf.edu

You should get – 139.62.234.57

You can try facebook.com? You should get – 157.240.14.35

Now if you type google.com or www.unf.edu in a web browser, you would go to the websites that you would expect. But what if you typed the number in the web browser? Well, that would work too – so typing 139.62.234.57 into a web browser would transport you to the University of North Florida home page. So what happens when you click on the mystery number below?

Click Me to enter a whole new world of shopping! >>> 54.239.17.7

Amazon.com!

There are web-based IP lookup sites if Terminal is not your thing – an example is IP Checker.

One final note. If you have purchased your own domain you may not have your own unique IP address and that’s because you are probably using what is known as “shared hosting” where a bunch of customers share a server with a single IP address. Obtaining your own IP address will cost extra, but unless you are a large organization or business, you generally don’t need it.

ICANN’s Beginner’s Guide to Domain Names (PDF)

Domain vs. Subdomain

One way that you can subdivide a domain is with a subdomain (or third-level domain). A subdomain is usually another computer server application that exists at the domain of an organization. The most common third level domain is www. There are many subdomains at the University of North Florida.

First off, unf.edu is the University of North Florida’s domain name. The .edu top level domain is unique in that in can only be registered to institutions of higher education, and only through the organization known as Educause – https://net.educause.edu/edudomain/ . You can’t get .edu as part of a personal domain name. Other restricted domains like .mil and .gov are unique because they are government owned as are country domains like .uk (United Kingdom), .es (Spain), and .it (Italy).

The following are examples of subdomains (or subdirectories) at UNF:

If you would like more information about how domains work on the UNF Faculty Domains system, you can read documentation on Domain Management, Registering a Domain, Setting Up Subdomains, and Subdomains vs. Subdirectories.

Photo by Sebastien Gabriel on Unsplash