What types of domain are there?

If you’re setting up a website or an online shop, choosing the right web address is an essential step. With multiple domain types and countless domain ex­ten­sions to consider, making the right decision isn’t always easy. What dis­tin­guishes top-level, second-level, and third-level domains, and which domain ex­ten­sions can you choose from?

Overview of domain types and available domain ex­ten­sions

A memorable web address, or domain, is made up of a suitable name and a matching domain extension. The following sections outline the five main domain types you should know when com­plet­ing a suc­cess­ful domain re­gis­tra­tion.

Domain type 1: Top-Level Domain (TLD)

Top-level domains (TLDs) form the highest level in the Domain Name System and appear at the end of a web address, for example .com, or .org. The al­loc­a­tion of TLDs is ad­min­istered by the IANA, a de­part­ment of the or­gan­isa­tion ICANN (Internet Cor­por­a­tion for Assigned Names and Numbers), founded in 1998. IANA de­term­ines which domain ex­ten­sions exist and grants dis­tri­bu­tion rights to re­gis­trars, which in turn work with domain providers to sell the more than 1,400 available domain ex­ten­sions, including classic TLDs, country-specific endings, and modern thematic domain ex­ten­sions.

Examples of original TLDs:

Domain type 2: ccTLDs (country code top-level domains)

ccTLDs are country-specific domain ex­ten­sions con­sist­ing of two letters, such as .de (Germany), .fr (France), or .us (United States). Each country defines its own re­gis­tra­tion rules. Some countries actively market their ccTLDs, for example Tuvalu with .tv.

The following table presents some country-specific TLDs as examples:

Domain type 3: gTLDs (generic top-level domains)

gTLDs cover thematic cat­egor­ies and are not tied to a specific geo­graph­ic location. Within generic domain ex­ten­sions, a dis­tinc­tion is made between two types:

Un­sponsored gTLDs are centrally overseen and ad­min­istered by ICANN, which co­oper­ates with various partners for this purpose. Ori­gin­ally, these ex­ten­sions were intended to be assigned only under certain con­di­tions. For example, the .net domain was meant to be reserved ex­clus­ively for internet service providers. Today, like many other un­sponsored gTLDs, it is available to busi­nesses, or­gan­isa­tions, and private in­di­vidu­als alike.

Sponsored gTLDs, on the other hand, are subject to the re­stric­tions set by the re­spect­ive sponsor. In this case, the re­spect­ive in­de­pend­ent companies or or­gan­isa­tions are also re­spons­ible for managing and con­trolling these gTLDs.

Modern new top-level domains such as .blog, .web, and .beauty also belong to the gTLD category.

Domain type 4: Second-level domain (SLD)

The second-level domain is the actual domain name, meaning the part before the TLD, for example ‘example’ in example.com. It is par­tic­u­larly important for branding and SEO because it can clearly describe the content of a project. A second-level domain is always re­gistered together with the chosen top-level domain.

There are even some country-specific second-level domains, as shown in the following table of com­bin­a­tions using the .uk TLD:

Domain type 5: Third-level domain (subdomain)

Third-level domains, commonly referred to as sub­do­mains, are placed before the second-level domain and help organise a website or divide it into separate sections.

Examples of third-level domains:

• us.example.org (U.S. version)
• en.example.org (English version)
• blog.example.org (blog section)
• app.example.org (web service/app)

Sub­do­mains make it possible to clearly separate different content without needing a new domain.

Tips for choosing the right domain

A basic un­der­stand­ing of the different domain types and domain ex­ten­sions helps you choose a clear, user- and search engine-friendly web address that fits your project without making the address un­ne­ces­sar­ily com­plic­ated. We have sum­mar­ised the most important tips for you.

Tip 1: Choose a suitable domain extension

The top-level domain can shape user ex­pect­a­tions and should align with your project:

• .shop signals e-commerce
• .blog indicates a blog
• .uk or .co.uk rep­res­ents a UK-based business
• etc.

Always choose a domain extension that appeals to your target audience and matches the content of your website.

Tip 2: Clear and memorable domain name

A good domain name should be short, clear, and easy to remember. The shorter the address, the easier it is for users to remember and enter it correctly. This reduces typos and improves the long-term vis­ib­il­ity of your website.

Tip 3: Use sub­do­mains only when needed

Sub­do­mains are useful when content needs to be clearly separated from the main website. However, for smaller websites, they are not always the ideal solution. You should therefore only use a separate third-level domain if you have a clear struc­tur­al concept.

A dedicated subdomain can be helpful in the following situ­ations:

• Sep­ar­at­ing different language versions
• Dis­tin­guish­ing core content from ad­di­tion­al sections such as a service area, blog, or forum
• Hosting a specific web service, such as an app or FTP server
• Operating an online store alongside the main website under the same second-level domain

Tip 4: Check avail­ab­il­ity and legal con­sid­er­a­tions

Make sure the domain you want is actually available. Common name vari­ations or versions with different domain ex­ten­sions can be re­gistered quickly. Also ensure that the name does not violate any existing trademark rights to avoid legal disputes.