What Are the Parts of a Domain Name, and What Do They Do? A Clear Guide to Knowing It All

Aristotle once said, ‘The whole is greater than the sum of its parts.” But it’s the parts of a domain name we care about. Learn about them in our guide.

Even if technology isn’t your jam, you probably know how to find a particular website: you type the company name into your browser, plus a dot-something bit on the end. As if by magic, your computer displays the site you want.

The company name and the dot-something are both key parts of a website’s domain name and URL. But what are they really called? What do they do? Are there any other bits you need to know about? What even is a URL, anyway?

Sit tight as we explain the parts of a domain name and how domains and URLs help us find our way around the Internet.

Why Are the Parts of a Domain Name Important? Make Me Care

So, why should you care about the different parts of domain names? Good question. As long as they’re doing their job, that’s all that matters, right? Hey, you manage to use smartphones and TVs without understanding their parts.

But if you’re setting up your own website, it helps to have a basic knowledge of domain name structure. We’ll get into that in a moment, but first let’s take a quick sidestep and explain what we mean by domains.

What Are Domains? (For Anyone Just Getting to the Party)

A domain is basically where your website lives. Domain names provide the address where people can find the site, like using a street address to find someone’s house for that party we mentioned.

Picture the Internet as a huge network of computers linked together. Each computer has an IP (Internet Protocol) address that tells others where to find it. IP addresses are made up of numbers and dots, which is great if you’re a machine. But if you’re a human, not so much.

That’s why we have the Domain Name System (DNS), which connects each IP address to a domain name that humans can understand. It means you can type www.onlydomains.com into your browser, instead of 119.252.177.37. We’re not all R2D2.

What Are the Parts of a Domain Name Called?

You might have noticed several different parts of a domain name. Three, to be exact. So, what’s in a (domain) name?

• Top-level domain (TLD): This is the bit after the dot, such as .com or .net. It’s also known as an extension or suffix.
• Second-level domain (SLD): This is the unique identifier, usually the business or brand name. It’s the meat in this sandwich between the two other domain parts.
• Third-level or subdomain (3LD): This goes before the identifier. It’s typically www. but it doesn’t have to be (more on that later).

What Do Each of the Domain Components Do? Everybody Works Here

All the components of a domain name play their part in getting you to the right place online. Let’s check out what they do.

Top-Level Domains (TLDs)

When you enter a web address, a lot happens behind the scenes. If you’re fascinated by the whole process, you can read more about TLDs. But here’s the quick version: TLDs help your computer, browser, and a network of servers to look up the right IP address.

There are many types. Generic TLDs (gTLDs) tell people what kind of website they’re looking at. For example, .com is usually for commercial businesses, and .org is for nonprofits (although those lines are blurred). Then there are the new kids on the block, like .shop or .info.

Country code top-level domains (ccTLDs) like .uk are assigned to countries and territories. But did you know some can be used in a trendy domain name? You’ll often see .ai (Anguilla) for artificial intelligence firms or .io (British Indian Ocean Territory) for tech startups. Even .co is also the ccTLD for Colombia.

Geographical TLDs (geoTLDs) are more specific, like .tirol for the state of Tirol in Austria or .eus to represent the Basque region and culture. Internationalised TLDs (IDN TLDs) use non-Roman script. And sponsored TLDs (sTLDs) are usually restricted to a specific field, like .gov or .edu.

Second-Level Domains (SLDs)

The SLD is usually your company name. The likes of Google or Amazon are so famous that they’re recognisable from one-word names. Other firms choose a name that tells people what they do (like OnlyDomains, although we actually offer far more than “only” domain names, just saying…).

SLDs should be simple and easy to remember. They’re limited to 63 characters (the shorter, the better) and can only have letters, numbers, and hyphens. When you put the SLD with the TLD, the two domain name components make up the unique address of your website.

Third-Level Domains (3LDs)

This may be hard to believe, but early website owners always put “www” at the start of domain names because, otherwise, users might not realise they were accessing a web application. Mind = blown.

Now that we all know our way around the Internet, there’s no need to use www unless you’re feeling nostalgic. If you just type in the SLD and TLD, your browser will still take you to the right website. But that doesn’t mean you can’t use a different third-level domain.

Subdomains let you label different areas of your website without having to register extra domain names. By using “blog” or “shop” instead of “www”, you can have a separate blog or store within your main website.

The main OnlyDomains address is onlydomains.com. But the customer support section is support.onlydomains.com. It’s neater than using subfolders, where you put the specific section after the TLD.

Important Components of Your URL

If TLDs, SLDs, and subdomains make up your domain name, what’s a URL? Well, it stands for uniform resource locator, and it’s the address of a specific page or resource on your website. A URL always has a protocol, a domain name, and a path, but it can also have other parts.

As an example, we’ll use the URL of an OnlyDomains support page with search results for the term “domain”: https://support.onlydomains.com/hc/en-gb/search?utf8=✓&query=url#:~:text=140%20results%20for%20%22domain%22

Protocol

The first part of a URL is called the protocol, scheme, or URL prefix. It tells your browser which set of rules it should use to find resources on your website. It’s always followed by a colon and two forward slashes (://), which reminds us of when we all used punctuation to create emojis 😉

The most common protocols are HTTP (Hypertext Transfer Protocol), which shows a web server and a browser how to communicate, and HTTPS (Hypertext Transfer Protocol Secure), which encrypts data with SSL (Secure Socket Layer). Others include mailto, file, news, FTP, POP, SMTP, or IMAP.

Subdomain

As discussed earlier, this is an optional part of a URL. You can use www or a word that represents a specific area of your site. In our example, it’s support.

Root domain

When you combine the TLD and SLD (like onlydomains.com), it’s known as the root domain. It represents your website as a whole. To be classed as part of that site, every page must include the same root domain in its URL.

Subdirectory/subfolder

This takes users to specific pages or resources on your website, helping to keep the content organised and easy to navigate for users and search engines. In our example, it’s hc/en-gb, which shows that you’re in our Help Center section, viewing the page in British English.

Port number

This number is often invisible to humans but is needed for every URL. Computers can see it with their superpowers. Port numbers identify applications or services on a system, and each server has its own port number. The default for HTTP servers is 80, and it’s 443 for HTTPS servers.

Pathname

This shows the location of the file or resource that the user wants to access and specifies the type of page requested. In our example, the pathname is search.

Query/query string

This starts with a question mark, which tells the browser that a specific query is being performed against a database. It comes before the query string, which sets the parameters for this data.

Parameters

Parameters are the values being queried during a search. They might appear as numbers, encrypted values, or search terms. Sometimes they look like gibberish to us, but they make sense to the machines running the show. Each query contains a key/value pair joined by the equals sign, with pairs separated by ampersands. Our query is utf8=✓&query=url

Fragments

These may appear at the end of a URL with a hash (#). They point to a specific section within the web page, such as a footer, sidebar, or a section of text. In our example, we highlighted and linked the words “140 results for domain”, so it appears as the fragment:  #:~:text=140%20results%20for%20%22domain%22

(We can feel your eyes glazing over. Don’t worry about all those weird % signs and numbers. Again, they make sense to the machines.)

URL vs Domain Name: What’s the Difference?

People often get the two confused, so here’s a handy table of the differences:

OnlyDomains Has You Covered For Everything Domains and Websites

Now that you know the parts of a domain name, you can crack on and set up your website. And that’s easy to do with OnlyDomains because we have everything you need in one place.

For starters, we have more than 900 domain name extensions to choose from. Just search for the name you want, see if it’s available, and register it in a few clicks. As well as registering, renewing, and transferring domain names, we can help you with the website itself.

Choose WordPress or Unlimited web hosting or create a site from scratch with the drag-and-drop website builder tool. Hosting packages come with free business email and an SSL certificate (so your URLs will start with HTTPS to show people they’re secure).

Ready to go? Find your ideal name with OnlyDomains