Domain levels form the foundation of every web address, which distinguishes sites and structures the internet’s hierarchy. Recognizing these levels helps clarify how domains function within the online ecosystem. For businesses and organizations, understanding domain levels ensures a professional, accessible, and recognizable online presence.
Let’s look into how domains interact with web hosting, explain their purposes, and help you select the right domain level in this guide.
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What Is a Domain?
A domain is part of the Internet where you can access a certain website. Often, it is referred to as a domain name since every domain on the Internet must have a unique name, which helps you identify and access the website.
Basically, what you see in your URL is the domain name of your site. All domain names use the Domain Name System (DNS) to translate the domain name into an IP address, which is used by computers to identify each other on the network.
For example, every site has a dedicated IP address usually in the form of numbers, such as 93.194.417.34. A DNS translates this into something humans can read, giving it a certain name, such as www.example.com. So, instead of typing numbers into your search bar, you enter the domain name, and the site appears.
Did You Know? There are over 350 million domain name registrations across all top-level domains (TLDs).
3 Types of Domain Levels Explained With Examples
Every domain name is constructed from three levels. These levels are also called parts of the domain name, but experts prefer the term “levels” since each builds upon the previous one to create the whole domain name.
The three parts of a domain name are:
Extra Info: There can be more than three levels to a domain. For instance, when using a country-code second-level domain (ccSLD), the previous second-level domain becomes a third-level domain, so the third-level domain now has to be a fourth-level domain. However, most sites today limit their domain names to three parts.
1. Subdomain
Also known as third-level domains, these are the parts that come after the second-level domain. In most cases (such as the example above), you can find them as the first part of the URL. They are used to give more clarity and structure to the domain. The most widely known subdomain is “www”.
In the past, subdomains were often used to let users know they were accessing a certain type of website. However, today, many websites no longer have the standard subdomain (www) or require you to add the subdomain when looking them up. Instead, there are now customized third-level domains.
Some businesses use subdomains to differentiate their sites with different languages, such as:
- en.businessname.com
- fr.businessname.com
- cn.businessname.com
- de.businessname.com
Others use subdomains to set up a mobile site; for example: m.businessname.com. Then, there are those that build and host a website on a different platform, such as Shopify, which requires including the platform’s domain. In this case, the site gets a different subdomain: businessname.shopify.com (businessname is the third-level domain now).
Extra Info: Theoretically speaking, every part after the top-level domain is a subdomain. Second-level domains are subdomains to top-level domains, third-level domains are subdomains to second-level domains, etc. But, since most sites use only three levels, subdomains are considered the final a.k.a. third part of the domain name.
2. Second-Level Domain (SLD)
A second-level domain is basically the name of your business. It’s the part of the URL that specifies the owner of the IP address. Unlike TLDs that can only be certain suffixes, an SLD can be literally anything.
The second-level domain is considered the key to every domain name for both users and SEO. This is because it can hold keywords and show what the content of the site is.
One type of SLD is the country-code second-level domain. These are used to further categorize a certain website in a certain country. For instance, in the US, each state has a ccSLD, so ny.us is reserved for websites in New York, pr.us for Puerto Rico, va.us for Virginia, etc.
3. Top-Level Domain (TLD)
A top-level domain is the final part or the extension of the domain name (basically, the first part you see starting from the right of the URL). Because of this, it’s also called domain ending. The three most widely known TLDs are:
- .com
- .net
- .org
The Internet Assigned Numbers Authority (IANA), a division of the Internet Corporation for Assigned Names and Numbers (ICANN), oversees the Root Zone Database — a list of the top-level domains. Today, this database counts 1,591 TLDs. According to the IANA, there are six types of top-level domains:
- Generic top-level domains (gTLD)
- Generic-restricted top-level domains (grTLD)
- Country code top-level domains (ccTLD)
- Test top-level domains (tTLD)
- Infrastructure top-level domain (ARPA)
- Sponsored top-level domains (sTLD)
Let’s look into each one separately.
3.1. Generic Top-Level Domains (gTLD)
Generic top-level domains are domains that everyone can use, hence the name. Right now, this group consists of:
- .com
- .net
- .org
- .biz
- .info
3.2. Generic-Restricted Top-Level Domains (grTLD)
Some generic top-level domains, although common, can’t be accessed by everyone. These are called generic-restricted TLDs and include domains such as .name and .pro. The domain .biz also falls into this (sub)group.
To register for these domains, you must meet the eligibility requirements set by the ICANN-accredited register. For example, the general requirements for registering a .pro domain include providing identification and proof that the individual or entity offers professional services, such as a license or certification.
3.3. Country Code Top-Level Domains (ccTLD)
Country-code TLDs are, as the name suggests, specific to a certain territory or country. To be able to register a domain with a ccTLD, you must fulfill pre-determined requirements like language, country registered business, permanent residency, etc.
For example, if you want to get a .us ccTLD in the US, you must be a US resident or citizen, or if you’re a foreign entity, then you must have a presence in the US.
Country-code TLDs are used to let search engines and users know that the services are only available for a certain region or are targeting specific audiences. Today, the leading ccTLD is .cn (China). Others include:
- .de (Germany)
- .uk (the UK)
- .ru (Russia)
- .us (the US)
- .nl (the Netherlands)
Tip: ccSLD and ccTLD are not the same. In the example .ny.us, the ccTLD is the suffix .us while the ccSLD is the state suffix. So .ny is the ccSLD, while .us is the ccTLD.
3.4. Sponsored Top-Level Domains (sTLD)
Sponsored top-level domains are domains used by a certain community because they’re sponsored by a representative of it. These communities can be based on anything — ethnicities, regions, professions, etc. and usually have strict requirements for obtaining a domain. So, if you’re not part of that group, your chances of purchasing a domain of this type are slim to none.
A common example that’s used to explain this type of top-level domain is the .aero domain. It’s sponsored by Société Internationale de Télécommunications Aéronautiques (SITA) and limits the use to only businesses in the air transport industry.
Other sTLD examples are:
- .edu
- .gov
- .int
- .mil
Up until 2012, ICANN didn’t differentiate the sponsored from unsponsored TLDs. Today, unsponsored TLDs are classified as generic TLDs (gTLDs) and generic-restricted TLDs (grTLDs).
3.5. Infrastructure Top-Level Domain (ARPA)
The domain .arpa is a top-level domain with a very specific use — managing the technical network infrastructure. It’s used even today but it is not available for public registration. Instead, subdomains are created, added, and managed by the Internet Engineering Task Force (IETF) for various technical purposes.
Historically, .arpa was the main domain of the ARPANET hosts — the predecessor of the Internet. With the development of the Internet, .arpa became one of the bases for TLDs we know and use today like .com and .edu. People initially thought that all systems would slowly migrate to different domains, but that proved to be more difficult than initially thought.
Hence, .arpa is still used today but only for maintaining the Internet infrastructure, including reverse DNS systems.
3.6. Test Top-Level Domains (tTLD)
Test top-level domains can be noticed by the .test domain. As the name suggests, they’re only used to test software and can’t be registered by anyone. Currently, there are 12 tTLD domains, all meaning .test but in different languages:
- .测试
- .परीक्षा
- .испытание
- .테스트
- .טעסט
- .測試
- .آزمایشی
- .பரிட்சை
- .δοκιμή
- .إختبار
- .テスト
Extra Info: Before IANA and ICANN, the original top-level domains were:
- .com (for commercial use)
- .org (for organizations)
- .net (for networks)
- .int (for international organizations)
- .edu (for educational purposes)
- .gov (for governmental agencies)
- .mil (for military structures)
Today, some of these are sectioned under generic TLDs, while others are sTLDs.
How Does Your Domain Name Benefit Your Business?
Clearly, the main benefit of having a domain is that your business will be visible online. But there are also some additional advantages, such as:
- Building brand identity and awareness: Having your brand displayed in your domain name lets customers know exactly where they are and what they can expect. The best hosting providers always allow you to choose between different domain names so you can set up one that best describes your brand. This will increase your reputation, which will inevitably bring more traffic and profit.
- Connecting with the market: A domain name, even one that’s parked, can be used to position you within a certain industry or geographic location. For example, if you use a ccTLD in your domain, you’re targeting customers in a specific country. An sTLD, on the other hand, positions you within an organization in a distinct niche or community.
- Adding credibility to your business: Every site that has a custom domain name is 10x more credible than those relying on a web host. By having your brand name in the URL, you’re letting customers know they’re in the right place, thus increasing trust and credibility.
- Improving SEO: Having a domain name for your business also affects SEO. It directly links to your business whenever users search for a similar keyword or your brand.
How To Choose the Right Domain Name and Type for Your Business
As you can see, finding the right domain name and type for your business can bring many benefits. However, you have to be careful in choosing the right domain name.
To ensure you get it right the first time, follow these three basic steps:
- Start with the top-level domain
- Choose a domain name related to your business
- Leverage subdomains for flexibility
1. Start With the Top-Level Domain
By choosing the type of TLD, you’ll have half the work done. To do that, think about these questions:
- What industry are you working in?
- What is your target audience?
- Where are you based?
- Where do you want your business to work?
With the answers, you can pinpoint the type of TLD you should have — country-coded, sponsored, restricted-generic, etc. Of course, you can always skip this step and use the generic top-level domain .com for your business site.
2. Choose a Domain Name Related to Your Business
The second-level domain is where your business name should go. Most companies use it to clearly indicate to their customers that they’re on the official site of the brand. Always consider these few tips when choosing the SLD:
- Keep it short and simple: A shorter domain is easier to type and remember.
- Avoid numbers, big letters in the middle, or hyphens: These can be confusing to visitors and make it hard to remember.
- Be specific and include your brand: Your SLD should reflect your business, brand name, or product.
- Think about SEO and keyword inclusion: Include relevant keywords to boost your search engine visibility.
3. Leverage Subdomains for Flexibility
Subdomains allow businesses to extend their web presence by segmenting content under a primary domain. For example, they can create distinct sections, such as a blog or store, without purchasing additional domains.
Using subdomains can also help with regional targeting, testing, or launching new product lines. This strategy keeps content organized while enabling customization to meet specific needs.
Additionally, integrating subdomains into your domain structure can enhance both user experience and site functionality, which support targeted campaigns or unique brand areas under a unified web identity.
Domain Level Takeaways
A domain name plays a significant role in establishing a business’s presence in its industry. It helps build brand awareness, increases your credibility on the market, and even has SEO benefits.
Every domain usually has three levels but remember that the TLD and SLD are the most crucial parts you need to consider. Go over the types we detailed above again and find the right domain name for your business using our simple 2-step guide.
If you need any help when creating your website, turn to professional web development companies and partner up for your next project!
