Domains Explained: The Complete Guide
A fundamental prerequisite for building a website or having a business email is a domain. Your website can’t go live until you register a domain name for it. But what really is a domain, how does it work, how do I choose a name, buy and register it? We break it all down for you in this comprehensive guide.
- What is a domain?
- Anatomy of a website address
- How domains work
- How DNS translation works
- Domain registry, registrars, and registrants
- ICANN and WHOIS Lookup
- How to buy and register a domain name
What is a domain?
A domain name is your website’s address on the internet. Just like you need the physical address of a home or shop to find it in the world, you need the domain of a website to find it on the internet.
Every website you’ve ever visited has a domain name.
www.google.com is Google’s domain name,
www.hostafrica.co.za is ours.
As you may have guessed, a domain name is unique, and can’t be shared.
Domain names may have characters A through Z, digits 0 through 9, hyphens
-, and a subset of the
ASCII character set (consisting of characters a through z).
Lastly, computers don’t recognise uppercase in domains, hence the use of the hyphen
- to separate words and make domains easier for humans and bots to understand. However, domains may not start or end with a hyphen
Anatomy of a website address
Now, understanding the different parts of a domain is confusing, because the internet is riddled with jargon that differs from the technical names. Let’s clear things up.
As with physical addresses, there’re hundreds of millions website addresses. The only way to navigate this many addresses is with systematic organisation. It works just like physical addresses.
Take a look at our address:
It consists of several labels separated by a comma. Each label identifies a location that gets more specific each time (from country to street number). Yes, you read this address with your eyes from left to right, but if you were to actually use it to find us, you’d start from the right to first identify the country, then narrow in on the city, suburb, street, and number.
In more technical words, addresses have a tree hierarchy that starts with the broadest identifier and narrows down to the most specific one. Same applies to web addresses:
A domain consists of several labels, separated by a dot. Each label points to a level and location within the Domain Name System (DNS), from broad to specific. This helps computers find exact locations of domains.
Starting from the first label called first-level (aka top-level) domain, computers read a web address from right to left, as indicated by the green arrow in the infographic below. Each label to the left is a subdivision (sub-domain) of the domain to its right.
Our graphic shows a typical 3 level Fully Qualified Domain Name.
It's important to note: technically, according to our graphic,
hostafrica specifies a sub-domain of the
.com domain, and
www is a sub-domain of
So, in theory, all domains below the TLD are a sub-domain of its right-hand domain, and actually, up to 127 sub-domains are allowed!
However, in practice, most websites nowadays follow the typical simple 3 level domain name. This is only because websites depend on humans to remember their domain names, so the shorter the domain, the easier it is to remember.
Fully Qualified Domain Name
Now that you understand a web address has levels and labels, you need to understand which labels are necessary to make up a domain.
A Fully Qualified Domain Name (FQDN) used to be considered a complete website address, and only requires 3 domain levels: the top-level domain (TLD) aka extension, the second-level domain (domain name), and third-level domain (sub-domain).
An example of a complete address is:
Knowing this distinction is important when deciding on what type of SSL you need for your website.
You might have noticed, however, these days it’s no longer necessary to type
www into your web browser to visit a site. So, if you need a super simple website, it’s perfectly okay to buy a domain name that’s just
hostafrica.com. Just be sure to read our above guide on SSL certificates to understand how it affects which type of SSL you’ll need for your website.
On the other hand, large company websites that span over many countries, products, and languages are better off using four or more domain levels to help users navigate large sites and improve Search Engine Optimisation (SEO). You can read more on the levels below to see more info on and working examples of this.
Next, we explain the function of each label so you can make an informed decision when you choose your domain name, and possible sub-domains.
Top-level domains (TLDs)
These are also called first-level domains as these are the first labels in the hierarchy of the DNS.
The colloquial name for TLDs are extensions (but beware of the context of this, as it mostly applies to the standard three level domain, like
.com is seen by laymen as the extension of
hostafrica, because visually it lies to the right of it. But as you now know,
hostafrica situated to the left, is actually a sub-domain of
As in the infographic, TLDs always sit at the end (visually) of your domain name e.g. www.google
.com, which belongs to the TLD
.com. There are many other TLDs, such as .
.co, etc. As a rule, TLDs may not be all numbers.
TLDs are regulated by IANA, a division of ICANN (Internet Corporation for Assigned Names and Numbers). They create TLDs and sell the rights to registrars, who let domain providers like us resell them to prospective domain owners.
In the beginning, there were only seven top-level domains, now there are more than 1,000.
Original seven TLDs OG TLD Original purpose Current purpose .com commercial entities (unrestricted) .org non-profit organisations (restricted) unrestricted .net network infrastructures (restricted) unrestricted .edu education tertiary education .gov governmental entities (restricted) .mil military (restricted) U.S. military (restricted)
The purpose of TLDs today is to give web users and search engines an idea of what your website is about.
Hence, TLDs are grouped into categories of what they were originally intended for when they were created, but most of these have lost their original purpose and used as owners see fit nowadays.
However, it's very important to note that Google uses TLDs as relevancy signals (meaning: it still has opinions on how these TLDs are relevant to users, so you should pay attention to them and pick wisely).
It’s vital that you choose a TLD that is relevant to your website. Let’s take a look:
Generic top-level domains (gTLDs)
These domains are mostly theme-based, portraying names of entities, commerce, activities, groups, entertainment, industries, faith, technology, professional, and even cities. Almost all gTLDs are open to the public to use.
Examples of gTLDs .com .org .net .capetown .tokyo .nyc .xyz .bid .abc .shop .blog .app .attorney .work .business .sport .beer .cafe .catholic .church .christmas .cloud .tech .dev .toyota .apple .amex
These three gTLDs are restricted:
.pro. They have designated guidelines that prospective registrants have to meet to be eligible.
Country-code top-level domains (ccTLDs)
As the name indicates, country-code top level domains (ccTLDs) are TLDs reserved for use in certain countries. Sometimes islands of a country get their own TLDs too.
ccTLDs always consist of two letters and are regulated by the domain authorities of the respective countries.
Examples of ccTLDs .za South Africa .uk United Kingdom .io British Indian Ocean Territory .us United States .de Germany .ru Russia .it Italy .fr France .ch Switzerland .es Spain .nz New Zealand .ck Cook Islands (territory of New Zealand)
The internationalised country-code top-level domains (IDN ccTLDs) were created for countries and regions that don’t use Latin characters, to display domains in, say, the Arabic alphabet or Chinese characters. Some domains are words e.g. السعودية (as-Suʻūdiyya) for Saudi Arabia.
SEO hint: If you’re targeting a global audience, then a country code TLD may be limiting, and you should consider a generic TLD like
com instead. This is because Google uses the ccTLD as a relevancy signal for that country’s audience, which means your website may rank better in that specific country.
If your target audience is local to your ccTLD, then this is a great advantage for your business. You can also choose different TLDs for your geographically distributed audience, like we do:
We use hostafrica.
co.za for our South African audience and hostafrica.
ng for our Nigerian clients, then my.hostafrica.
com for our global shop and client area.
Sponsored top-level domains (sTLDs)
These domains are sponsored by communities or organisations. sTLDs are restricted to the specific group/community the sponsor represents, e.g. industries, geographical regions, cultural community, government, treaties, etc.
All sTLDs .edu U.S. institutions of tertiary education .gov U.S. governments .mil U.S. military .travel Travel agents, arlines, hoteliers, tourism bureaus, etc. .aero Air-transport industry .post Postal services .asia Companies, organisations in Asia-Pacific region .cat Catalan linguistic and cultural community .int International treaty-based organisations .jobs Human resource managers .museum Museums .xxx Pornographic sites .tel For businesses and individuals to publish contact data .coop Co-operative associations
Infrastructure top-level domain
Managed by the Internet Architecture Board,
.arpa is the only domain in this category. It’s designed for network infrastructure.
Second-level domains (SLD)
In a typical three-level domain like
www.hostafrica.com, the SLD is
hostafrica. This is why it’s often referred to as the
domain name as it usually represents the website’s name, which in turn often represents the company’s name.
For the best SEO and user experience, the domain name should describe the content of the website as much as possible.
However, if you have a country-specific SLD, then this will technically be the second-level domain as it’s a sub-domain of the TLD. An example of this is very often used in
- South Africa:
.co.zais used to describe a company
.coin South Africa
.co.uk(same as above),
.sch.uk(schools in the U.K.)
So our website
www.hostafrica.co.za is a four-level domain:
.za is the top-level domain (TLD),
.co is the second-level domain,
hostafrica is the third-level domain, and
www the fourth.
In a typical three-level domain like
www.hostafrica.com, the third-level domain is usually the
www. But this is open to much creativity.
These days companies use the third-level domain to distinguish a specific branch in a country, or a language, or a function of their website:
en.hostafrica.com (the code for English language)
us.hostafrica.com (country code for The U.S.A)
blog.hostafrica.com (website function)
As mentioned above, third level domains aren’t necessary for creating a working domain name. e.g.
hostafrica.com will work just as well.
Note: Companies also use the third-level domain space to place hostnames. A hostname is the name of a computer/device, usually a web server. This is an easy way to name and remember internal company devices. While available to the internet, these are usually private domains.
So if the company’s emails are hosted on their own server, their mail server might be called
Other examples are:
How domains work
The internet is a very large network of interconnected computers. These computers, like the one you are using to read this blog, and the one hosting our website, communicate with each other using unique IP addresses.
A typical IP address looks like this: 22.214.171.124. Now, for computers, remembering this long numeric code isn’t a problem. But for humans, it will be virtually impossible to remember IP addresses of all their favourite websites.
This is why a smart guy, named Paul Mockapetris, came up with the idea of domains. This was revolutionary because it allowed people to access websites using their names, which was much more convenient.
Note that using domains doesn’t mean that we have removed IP addresses from the equation. They’re still there, just hidden from the end-user. What happens is that we create a mapping between the name of the website and its IP address.
When a user enters a domain name in their address bar, behind the scenes, it gets translated into the website’s IP address. This process is known as DNS translation or lookup. The translated IP is then used to access the website. But how does this translation occur? And who stores the mapping?
How DNS translation works
To visualise the process of DNS translation, consider the above image.
- The user enters the address
www.hostafrica.co.zain their browser.
- The request is sent to the closest DNS server. A DNS server is like the phonebook for the entire internet. Upon receiving domain name information from the browser, the DNS server converts it into its corresponding IP address and returns it to the browser.
- The browser uses the IP address to send an HTTP request to the actual server hosting
- The server then sends an HTTP response to the browser, which is used to display the website to the user.
Sometimes a DNS server doesn’t have the mapping information for a particular domain name. In that case, it sends a request to another DNS server, close to it. The process continues until a DNS server with the relevant record is found.
Once that happens, the response trickles back to the original DNS server, which sends the response to the client browser. All the queried DNS servers also update their databases with the new record, to avoid having to relay the request again.
Domain registry, registrars, and registrants
A domain name needs to be purchased and registered before it can become your website’s identity. A domain name registry is an organization responsible for managing top-level domains. They develop extensions, set appropriate rules for domain usage, and collaborate with registrars to sell domains.
A registrar is an entity, accredited by the ICANN, (the main internet regulatory body) to sell domain names to registrants. Some registrars can only sell certain domains, like TLDs, or ccTLDs.
A registrant is a person who purchases a domain from a registrar and gets it registered with a registry. If ever a registrant wants to change their domain’s settings in the registry’s database, they request their registrar to do so.
ICANN and WHOIS lookup
ICANN oversees all the domain registration activities performed by the registries and registrars. As a registrant, when you purchase and register a domain, you become its sole owner, for the specified registration period.
Post-registration, domain owner details, along with other information, is publicly available via WHOIS lookup. WHOIS is a querying protocol used to retrieve information on registered internet resources, such as domain names, IP addresses, and name servers.
A WHOIS domain lookup will allow you to determine whether a domain is available, when it was registered, when it will expire, where it was registered, the registrar it was registered with, DNS information (the name servers it points to), domain status, and more.
A WHOIS my IP search will help you find your current IP address and can even retrieve a host of other information. Curious?
Use our WHOIS IP lookup using any IP address or domain name to find more information:
Lastly, domain registration can be renewed indefinitely. The maximum allowed registration period of a domain is 10 years. Most registrars give you the flexibility to de-register a domain at any time, however some may charge you a fee for doing so.
How to buy and register a domain name?
Wondering how to buy and register a domain name for your website? Here’s how:
- Decide on your domain name: Your domain name will be your brand’s identity. It’s what customers will tell their friends when praising your products. You want it to be something catchy, easy to remember, and expressive.
- Check for availability: The next step is to check whether your dream domain name is available. You may have just thought of the best possible domain name for your business, but if it’s already taken by someone else, try a variation of it instead.
- Choose a registrar: Once you’ve found the perfect domain name that’s also available for registration, you need to find a registrar. Registration and renewal prices may vary from registrar to registrar.
- Make the purchase: After you’ve chosen the right registrar, make the payment to transfer ownership of the domain to your name.
- Wait for DNS propagation to complete: Once registration completes, the domain’s information is propagated to DNS servers around the world. The process can take up to 24 hours to complete, making your new domain, ready for use.
What are the 4 types of domains?
There are four types of top-level domains (TLDs):
- Generic top-level domain (gTLD): general purpose domains that’re theme based and open to the public.
- Country-code top-level domain (ccTLD): two letter domains that represent countries and island.
- Sponsored top-level domain (sTLD): domains that’re sponsored and limited to the specific group/community the sponsor represents, e.g. industries, geographical regions, cultural community, government, treaties, etc.
- Infrastructure top-level domain: Managed by the Internet Architecture Board,
.arpais the only domain in this category. It’s meant for network infrastructure.
What are the top 5 domains?
The top 5 top-level domains are:
- .com: Hands down the most popular TLD available. It’s also everyone’s first choice. Most of the time, if someone doesn’t choose a
.comdomain, it’s because it’s already taken.
- .net: was originally reserved for ISPs and networks, but has now become a generic, openly accessible domain. The general opinion regarding
.netdomains is that they are associated with web applications and services.
- .org: was originally reserved for non-profit organizations, but is now available to everyone. People typically perceive
.orgwebsites as trustworthy and legitimate.
- .co: was originally reserved for the country of Colombia, but is now available to the general public. If you are building a website for your business, then a
.codomain is a viable choice.
- .us: Unlike the top 4,
.usdomains are reserved for people and companies in the United States. It was originally used only by the U.S. government.
What do I need to know before buying a domain name?
A domain name will be your business’ identity, so you need to choose wisely. Here are a few considerations to keep in mind:
- Competitive analysis: What kind of domain names have your competitors chosen? And how well-received are they? If there’s a keyword that most of your counterparts use, then it’d make sense to include it in yours as well.
- Easy to remember and type: Needless to say, the domain name must be both, easy to remember, and type. Don’t use a complicated word, which people are likely to get wrong.
- The shorter, the better: Short and expressive domain names are the way to go. Nobody wants to visit
- There is a world beyond
.com: Restricting yourself to a
.comdomain can sometimes make it impossible to find a worthy, unregistered name.
- Avoid hyphens and numbers: Hyphens are great for readability, but are also hard to remember and convey. The same is true for numbers. Do you mean
Does it matter where you buy your domain name?
Yes, it absolutely does. Choosing the right registrar is very important while buying and registering your domain name. Here’s what you need to consider:
- There shouldn’t be hidden costs: Some registrars pull customers in by giving astonishingly low registration rates but then include many hidden charges in their subscriptions.
- Privacy protection: Domain and registration details are public records, which can be misused by attackers. This is why you should look for registrars that offer privacy protection for your data.
- Once again, transparency: Some providers will try to hide their renewal rates, in the tiniest of fonts possible. The reason is usually that their renewal charges are much higher than their registration prices. Find a registrar that shows maximum transparency in their dealings.
- Client support: A host can make or break your business. If ever you need to de-register a domain, want changes, or want to buy website and email hosting with your domain, hosting with a reliable, expert provider is vital. Look for a registrar with a reputation for outstanding support.
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