Domain Types: Definition, Examples & How To Use Them

Updated by Chima Mmeje — April 25, 2025.

A domain name is a unique, human-readable address that directs users to a website. It serves as an easier alternative to numerical IP addresses, allowing people to access websites with recognizable names instead of long sequences of numbers.

Domains are a critical part of how the internet functions, acting as an identifier that connects users to the correct website. 

A domain name consists of three main parts:

• Top-Level Domain (TLD): The extension at the end of a domain (e.g., .com, .org, .net).
• Domain name: The unique part of the domain chosen by the owner (e.g., example in example.com).
• Subdomain (optional): A prefix that extends the root domain (e.g., blog.example.com).

The combination of the SLD and TLD forms the root domain (e.g., example.com). While "http://" or "https://" appears in a website URL, this is part of the protocol and not the domain name itself.

There are several types of domains, each with its own characteristics and uses. Understanding the different types of domains can help website owners choose the most suitable and effective domain name for their online presence and influences your site’s visibility.

Let’s look at each of these elements more closely:

1. Top-level domain

A top-level domain (TLD) is the last part of a domain name, appearing after the dot. It is the highest level in the domain name system (DNS) hierarchy and helps categorize websites based on purpose, geography, or industry. These categorizations are often referred to as domain name extensions.

Common examples of TLDs include:

• .com – The most popular and widely recognized TLD
• .org – Commonly used by nonprofit organizations
• .net – Initially intended for network-related businesses but now widely used
• .edu – Reserved for educational institutions
• .gov – Used exclusively by government entities

Subsets of top-level Domains include:

Generic Top-Level Domains (gTLDs)

Generic Top-Level Domains (gTLDs) are a type of top-level domain that is not tied to any specific country and can be used by Generic top-level domains (gTLDs) expand beyond traditional TLDs and are often used for branding and niche markets. 

They provide greater flexibility for businesses and individuals to create industry-specific or personalized web addresses. 

Domain name extensions play a crucial role in categorizing different types of websites based on their functions and audience.

Managed by the Internet Corporation for Assigned Names and Numbers (ICANN), gTLDs are available for registration through accredited registrars.

Examples of gTLDs include:

• .tech – Ideal for technology-focused businesses
• .store – Commonly used by e-commerce and retail websites
• .app – Designed for mobile apps and software-related sites

These extensions help brands stand out and improve domain availability when popular TLDs like .com are already taken

Country-code Top-Level Domains (ccTLDs)

Country-code top-level domains (ccTLDs) are two-letter extensions assigned to specific countries or territories. They help businesses target local markets and improve regional search visibility.

Examples of ccTLDs:

• .us – United States
• .uk – United Kingdom
• .ca – Canada
• .de – Germany

Businesses often use ccTLDs to establish a stronger local presence and increase trust with users in specific regions. Google treats ccTLDs as signals for country-specific search rankings, making them beneficial for SEO in local markets.

Sponsored Top-Level Domains (sTLDs)

Sponsored top-level domains (sTLDs) are restricted domain extensions maintained by specific organizations or industries. They require approval or documentation to register.

Examples of sTLDs:

• .gov – Reserved for U.S. government agencies
• .edu – Limited to accredited educational institutions
• .mil – Used exclusively by the U.S. military

Since these domains are restricted, they increase credibility and ensure that only verified entities can use them.

2. Second-level domain (SLD)

A second-level domain (SLD) is the main part of a domain name, appearing before the TLD. It is chosen by the owner and represents the business or website identity. 

The domain hierarchy places SLDs below TLDs, but SLDs often play a more significant role in SEO and user perception.

When selecting a domain name, it is crucial to check the availability of your desired domain using registry tools and consider various extensions if the primary choice is unavailable.

Example:

• In example.com, “example” is the SLD, and “.com” is the TLD.

A strong SLD contributes to brand recognition and helps create a memorable web address. If you’re trying to decide on a domain name, check out this Whiteboard Friday on How to Choose a Domain Name.

3. Root domain 

While the term “root domain” was originally created in the context of DNS (domain name servers), a root domain typically consists of a second-level domain (SLD) and a top-level domain (TLD). 

Your website’s root domain is the highest page in your site hierarchy (probably your homepage). Individual pages or subdomains can be built off the root domain, but each page URL must technically include the same root domain in order to be a part of your website.

Example:

• example.com is a root domain
• blog.example.com is a subdomain of example.com

The root domain is where the website’s authority is built, making it a critical part of an online presence.

4. Subdomain

A third-level domain, also known as a subdomain, is a prefix added to a root domain that helps organize website content. Businesses use subdomains to separate sections of their site without creating a new domain.

Examples of subdomains:

• blog.example.com for a company blog
• shop.example.com for an e-commerce store
• support.example.com for customer service

Google treats subdomains as separate entities, which means they do not always inherit the SEO value of the main domain. However, these third-level domains are useful for structuring large websites. These are also the subdomains that commonly result in canonicalization errors.

5. Internationalized domain names (IDNs)

Internationalized domain names (IDNs) allow non-Latin characters in domain names, enabling websites to use scripts such as Arabic, Chinese, Cyrillic, and others.

Purpose of IDNs:

• Expands internet accessibility for non-English speakers
• Enables websites to use domain names in native languages
• Helps brands connect with global audiences

These domains function similarly to standard domains but may use Punycode (an encoding system) to ensure compatibility with the DNS. 

By enabling users to register domain names in their local languages, IDNs enhance accessibility and make it easier for users to find and remember domain names.

To maximize search engine visibility and improve rankings, it is important to follow SEO-friendly domain name practices.

Make your domain name memorable 

A domain should be short, easy to spell, and pronounce to ensure strong brand recall. Simplicity helps with word-of-mouth marketing and improves processing fluency, a cognitive bias where people associate easily processed words with trust and familiarity. 

A relevant domain can also help search engines identify the business type or industry of a website, enhancing its credibility and potential for gaining backlinks.

Best practices:

• Keep it under 15 characters for readability
• Avoid numbers, special characters, and complex spellings
• Prioritize brandability over generic terms

Because of search engine’s growing reliance on accessibility and usability as a ranking factor, the easier a domain (or URL) is to read for humans, the better it is for search engines.

Use broad keywords where it makes sense

Including a keyword in your domain can help clarify your niche but should be used sparingly. Keyword-stuffed domains (e.g., best-cheap-laptops-online.com) often appear spammy and may face ranking challenges.

We mentioned this earlier, but it's worth mentioning again: While these types of domain names once carried weight as a ranking factor, their tendency to be associated with low-quality content means searchers (and search engines) may now view these keyword-dense domain names with a negative bias.

What works:

• Subtle, brand-friendly keywords (e.g., LawnCarePros.com instead of BestLawnCareServices.com)
• A balance between branding and relevance

What to avoid:

• Exact match domains that look unnatural
• Overuse of hyphens or repetitive words

Google has de-prioritized low-quality keyword-rich domains in favor of high-quality content. If using a keyword, ensure the domain adds value and is user-friendly.

For more on this topic, read The Exact Match Domain Playbook: A Guide and Best Practices for EMDs.

Avoid hyphens if possible

Hyphens may improve readability, but they are strongly correlated with spammy domains and reduce trustworthiness. Search engines and users favor clean, hyphen-free domains.

Best approach:

• Avoid hyphens unless necessary
• If using them, limit to one hyphen (e.g., high-quality.com, not best-online-shopping-deals.com)

Use .com over other top-level domains (TLDs)

While TLDs don’t directly impact rankings, .com domains are the most widely recognized and trusted. Users often assume a website ends in .com, leading to higher direct traffic.

TLD recommendations:

• .com is ideal for global branding
• .net and .co are acceptable if .com is unavailable
• Country-code TLDs (ccTLDs) like .uk, .ca, or .de help with local SEO

What to avoid:

• Low-quality TLDs like .biz, .info, and .name, often have lower trust and CTRs
• Using unfamiliar extensions unless they align with your niche (e.g., .tech for tech startups)

Use subfolders/subdirectories instead of subdomains

Google treats subdomains (blog.example.com) as separate entities from the main domain, meaning they may not inherit the same authority. 

Subdirectories (example.com/blog) are generally preferred for SEO because they consolidate ranking signals under the main domain. 

However, subdomains can be useful for separating distinct sections of a website, such as support pages or international versions.

Best practice:

• example.com/blog/ (Preferred for SEO)
• blog.example.com (Less effective unless separating content by region/language)

Exception:

 For multilingual websites, subdomains like fr.example.com may be beneficial.

Don't obsess over domain age

Many believe that older domains rank better, but Google has clarified that domain age is not a ranking factor. The age of a website’s content and backlink profile matters more than how long a domain has been registered.

When asked about domain registration length, Google's Matt Cutts said, 

"To the best of my knowledge, no search engine has ever confirmed that they use length of registration as a factor in scoring. If a company is asserting that as a fact, that would be troubling. The difference between a domain that's six months old and one year old is really not that big at all.”

What actually matters:

• First indexed date (when Google first crawled the site)
• Quality and quantity of backlinks over time
• Content freshness and authority

Establish credibility and trust

A professional domain name helps establish credibility and trust. Businesses using custom domains like example.com appear more legitimate compared to those using free subdomains like example.wordpress.com. 

Improve brand recognition and online visibility 

A well-chosen domain name strengthens brand identity and improves recognition. Short, memorable domains are easier for users to recall and type correctly, increasing direct traffic. 

A relevant domain can also help search engines identify the business type or industry of a website, which is beneficial for gaining backlinks and enhancing ranking on search engine results pages.

The choice of a top-level domain (TLD) also plays a role in branding. A dot com domain is widely recognized and trusted, while niche-specific TLDs like .tech or .store can reinforce industry relevance.

Increase click-through rate and local search rankings

TLDs themselves do not directly impact rankings, but they can affect user trust and click-through rates. Generic TLDs like .com tend to perform best because they are widely recognized.

Country-code TLDs (ccTLDs) like .uk or .ca help target regional audiences and improve local search rankings, making them beneficial for businesses focused on specific geographic locations.

Choose a clear, memorable, and trustworthy domain to strengthen your brand and improve visibility. Secure your ideal domain early and follow SEO best practices to maximize long-term success.

What are the five top-level domains?

The five most common TLDs are .com, .org, .net, .edu, and .gov.

Do domain names impact SEO?

Domains don't directly affect rankings, but branding, memorability, and keyword use can influence SEO.

Does changing a domain name affect SEO?

Yes, changing domains can impact rankings. To minimize loss, use 301 redirects, update links, and monitor traffic.

Does the domain extension affect SEO?

TLDs don’t impact rankings, but ccTLDs help with local SEO. Generic TLDs like .com are trusted globally.

Is .com best for SEO?

.com is the most recognized and trusted but does not get a ranking boost over other TLDs.