What is a Subdomain? Everything You Need to Know

Key highlights

• Know what is a subdomain and how it works as part of your main domain.
• Learn the differences between subdomains, subdirectories and second-level domains for better site structure.
• Explore practical examples like blog subdomains, eCommerce subdomains and support subdomains.
• Understand how subdomains impact SEO and when to use them strategically.
• Uncover step-by-step guidance on how to create a subdomain with Bluehost.

As your business grows, so does your desire for a website that can land new clients, convert leads and manifest your plans. However, challenges arise when trying to fit expansive ideas into a simple business website. This often happens because a single website may not be equipped to handle everything effectively.

Did you know you can easily create multiple separate websites from your domain to organize content and manage business needs? You can if you know how to create a subdomain and learn what is a subdomain, watch our video tutorial for step-by-step guidance.

What is a subdomain? 

A subdomain is a prefix added before your main domain name that creates a distinct section of your website. Think of it as a unique web address branching off your primary domain, designed for specific content, services or audiences.

Subdomain example:

• blog.example.com: a blog subdomain for publishing articles
• shop.example.com: an eCommerce subdomain for your online store
• support.example.com: a help center or customer support hub
• mail.example.com: dedicated to email services
• www.example.com: the default subdomain for your main website

You can imagine a subdomain like an apartment in a larger building. The building is your root domain and each apartment (subdomain) has its own entrance, function and layout, while still being part of the same property.

This structure lets you organize content, expand your brand, test new ideas and run separate websites without disrupting your main site. When used strategically, subdomains improve website navigation, SEO purposes and user experience, making them a valuable tool for both businesses and personal projects.

The differences between a subdomain vs subdirectory

When organizing your main website, you have two common options: creating a subdomain or using a subdirectory. While they may look similar in a URL, their structure and purpose are very different.

A subdomain is a prefix before your primary domain name, such as blog.example.com or shop.example.com. Each one acts like a separate website with its own design, platform and sometimes even hosting provider. Businesses often use subdomain examples like blog subdomain for articles or eCommerce subdomain for an online store.

A subdirectory, on the other hand, is a folder within your main domain for example, example.com/blog or example.com/shop. It remains part of the main website and shares the same site structure, design and SEO authority as your primary domain.

Think of it this way:

• A subdomain is like building a new apartment inside your property with its own entrance, rooms and style.
• A subdirectory is more like adding a new room inside your existing apartment, it still shares the same main structure.

Both are valid approaches, but your choice depends on your goals. If you want a separate website (for an online store, testing or different language versions), go with a subdomain. If you want to keep everything under one roof and boost search engine optimization for the main domain, a subdirectory may be the better choice.

Subdomain vs subdirectory: quick comparison

Feature / Factor	Subdomain (e.g., blog.example.com)	Subdirectory (e.g., example.com/blog)
URL structure	Prefix before the main domain (subdomain name)	Folder path after the primary domain
Relation to main website	Functions as a separate site	Remains part of the main website
SEO purposes	Treated as a separate domain by search engines	Inherits SEO value from the primary domain
Domain authority	Does not share authority with the main domain	Gains strength from the main domain
Use cases	Blog subdomain, eCommerce subdomain, testing site, language versions	Organizing website content or categories within the main site
Hosting & management	Can use a different hosting provider or domain registrar	Managed under the same hosting plan
Scalability	Good for separate sites with different functions	Best for maintaining a single site structure
Examples	shop.example.com, support.example.com, en.example.com	example.com/shop, example.com/help

How to create a subdomain (step-by-step)

A subdomain structure includes the subdomain name followed by a dot and your main domain name (e.g., “blog.example.com”). This structure helps organize content on your website.

Bluehost, a reputable web hosting provider, offers user-friendly tools for managing subdomains. Follow these steps:

Step 1: Log in to your hosting account

• Sign in to your Bluehost Account Manager.
• From the left-hand navigation, click on the Hosting tab.

Step 2: Open cPanel

• Under Quick Links, select cPanel.
• In cPanel, locate the Domain Names section and click Domains.

Step 3: Add a new subdomain

• Click the Create a New Domain button.
• Enter your desired subdomain name (e.g., blog or shop) in the Domain field.
• Uncheck “Share document root (/home/username/public_html) with domain.tld” so it points to its own folder.

Step 4: Assign a directory

• Choose or create a directory where your new subdomain website content will be stored.
• It’s best to name the folder after your subdomain for easy management.
• Click Submit to finish setup.

You’ve now successfully created a subdomain. For more step-by-step guidance, check out our detailed Knowledge Base article How To Create A Subdomain.

What is a subdomain used for?

A subdomain is more than just a technical feature, it’s a powerful way to expand, organize and optimize your main website. By creating subdomains, you can set up separate websites under your primary domain, each with its own content, design and purpose. Here are the most common uses and benefits of subdomains:

1. Organizing website content

2. Branding and expansion

3. SEO purposes

4. Improved security

5. Better website navigation

6. Marketing campaign tracking

7. Targeting specific audiences

8. Staging and development sites

Let’s discuss each of these subdomain use cases in detail so you can understand how they work and when to use them.

1. Organizing website content

Subdomains allow you to organize content into dedicated spaces. For example:

• blog subdomain: blog.example.com for articles and resources
• eCommerce subdomain: shop.example.com for your online store
• support subdomain: support.example.com for FAQs and customer help

This keeps your website content clean and structured, improving both site structure and user experience.

2. Branding and expansion

Businesses often use suseparate sites that strengthen their brand identity. For example, a university might create subdomains for each campus, while a news company could launch subdomains for sports, business or entertainment. Subdomains help you reach the right target audience without cluttering your main website.bdomains as

3. SEO purposes

From a search engine optimization standpoint, subdomains can target specific keywords and audiences. Since search engines treat subdomains as independent websites, you can optimize each one separately. For instance, an eCommerce site might use a dedicated subdomain to rank for “online store” searches, while the main domain focuses on brand keywords. This expands your domain authority reach and helps capture more organic traffic.

4. Improved security

By isolating sections of your primary site, subdomains add an extra layer of security. If one subdomain website is compromised, other subdomains and the main domain remain unaffected. This separation reduces overall risk.

5. Better website navigation

Large websites often become overwhelming. Subdomains create a clear URL structure that makes website navigation smoother. Visitors can directly access the content they need without digging through layers of pages on the main site.

6. Marketing campaign tracking

Businesses can create subdomains to track marketing campaigns. For example, promo.example.com could host a seasonal campaign. This makes it easier to monitor engagement, conversions and traffic separately, helping refine future strategies.

7. Targeting specific audiences

Subdomains are effective for targeting different demographics, languages or regions. Examples include:

• en.example.com for English content
• fr.example.com for French content
• eu.example.com for European visitors

This approach ensures language-specific content and geo-specific content without confusing your global audience.

8. Staging and development sites

Developers often create staging subdomains (e.g., staging.example.com) to test new designs, plugins or features. This keeps experiments separate from the main website, ensuring a smoother experience for visitors while still allowing teams to build, test and improve.

In short, subdomains give you flexibility to run different subdomains for blogs, stores, support or testing while keeping your primary domain name intact. Whether for SEO purposes, branding or targeting specific audiences, they’re a practical way to create subdomains that organize your digital presence and enhance your online store, blog content and website sections effectively.

Subdomain examples

Now that we’ve answered the question “what is a subdomain,” let’s explore real-world examples. Subdomains are flexible tools that businesses, organizations, and individuals use for specific functions, better website content organization, and an enhanced user experience.

Below are the most common subdomains and their use cases:

1. eCommerce (online store separate)

Running an online store separate from your main website often requires its own subdomain extension. For example, store.playstation.com hosts PlayStation’s digital shop. Using an eCommerce subdomain allows for advanced payment processing, product pages, and integration with an eCommerce platform without interfering with the primary site’s performance.

2. Mobile sites

Many platforms create unique subdomains for mobile versions. For example, m.facebook.com offers a layout optimized for mobile devices. Even though responsive design is now common, mobile subdomains still exist to ensure an enhanced user experience across mobile devices in the world wide web.

3. Location-based subdomains

Companies often create geo-specific content by using location subdomains. For example:

• uk.yahoo.com → UK content
• us.yahoo.com → U.S. content

This method makes it easier to serve different subdomains for regional markets while keeping everything tied to the second-level domain (yahoo).

4. Audience segmentation

Businesses use own subdomains to target specific audiences. For instance:

• ride.lyft.com → general users
• autonomous.lyft.com → self-driving project enthusiasts

This strategy provides separate websites for different groups while staying under one larger domain.

5. Blog subdomain

A blog subdomain helps businesses publish articles without cluttering the main website. For example, blogs.loc.gov organizes the Library of Congress’s blog content. By separating blogs into a subdomain website, you can create content around new keywords and improve search engine optimization.

6. Support centers & FAQs

Dedicated support subdomains like support.bluehost.com host customer service portals. These platforms often include subdomain FAQ sections, tutorials, and ticketing systems. Isolating support on a separate subdomain improves navigation and adds security with SSL certificates.

7. Content hubs

Media companies often use subdomains for popular subdomains dedicated to niche content. For example, cooking.nytimes.com is part of the New York Times but focuses only on cooking. This specific function signals authority to search engines and delivers tailored website content.

8. Language versions

For international reach, brands create different language versions via subdomains:

• es.wikipedia.org → Spanish Wikipedia
• en.wikipedia.org → English Wikipedia

This approach keeps the URL structure clean and is a best practice in international SEO.

9. Forums & message boards

Community platforms often run on forum subdomains. Example: forum.wordreference.com enables users to interact on message boards separate from the main dictionary site. This ensures a smoother site structure while maintaining community forums content.

10. Function-based subdomains

Some brands use subdomains for special projects or initiatives. Example: smile.amazon.com, where Amazon donates a percentage of purchases to charity. This specific function creates value while still linking to the primary domain name.

11. Product-specific subdomains

Large platforms often separate products into unique subdomains. For example:

• chat.example.com
• analytics.example.com

This structure improves website navigation and helps users quickly find what they need without affecting the main site.

12. Knowledge & academies

Educational hubs frequently use academy subdomains for tutorials, training, and certifications, e.g., academy.example.com. This keeps learning material separate, improves authority, and allows businesses to create content around knowledge sharing.

Extra notes:

• You can have multiple subdomains, so if you’re wondering “how many subdomains” you can create, the answer is: as many as your hosting provider and domain registrar allow.
• Each subdomain is tied to your domain name system (DNS) and works alongside your second-level domain and top-level domain (TLD).
• Always secure your subdomains with SSL certificates to maintain trust and SEO rankings.

Subdomains are versatile. From eCommerce platforms to support centers, blogs, forums, and regional websites, they give you the flexibility to run separate sites under one domain name while enhancing both SEO purposes and user experience.

How do subdomains affect SEO?

Subdomains are relevant when it comes to organizing your website and content layout efficiently. When used correctly, subdomains offer several benefits for business growth.

However, Google and other search engines count subdomains as entirely different websites from their primary domains. The benefits you get from backlinks to your main website belong only to your primary domain. 

This can affect your subdomain’s search engine optimization (SEO) negatively. It takes equal effort to rank a subdomain as it takes your main website. But, if you have several brand keywords you want to rank for, subdomains can be a fast way to rank for each and boost your SEO keyword ranking. 

Create subdomains when you need them for specific reasons, such as setting up your online store or targeting a particular audience. Essentially, using a subdomain properly will not affect your website’s SEO. But it is better to maintain a single domain if you don’t have a genuine reason to create a subdomain.

Knowing how to create a subdomain to manage your business needs will boost your brand growth. Creating subdomains makes it easy to organize and structure your brand website development. Knowing what a subdomain is will help you use its advantages for both your business and your audience.

To learn more about SEO strategies that help grow your business and website, watch our video how to grow your business with SEO.

Final thoughts

Utilizing subdomains is a valuable tool for enhancing the functionality and organization of your website. As your business expands, the need to connect to different audiences, test new ideas and organize content becomes paramount. This is where subdomains come into play, offering a flexible solution to various challenges in web development.

Ready to build a functional website that empowers you to create subdomains easily? Check out Bluehost’s web hosting packages today.

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