What are Subdomains? (Definition and Examples)

Hey there!

As an experienced webmaster with over 15 years in the industry, I know subdomains can be confusing at first. But trust me, mastering subdomains is crucial for organizing and managing your online presence.

In this comprehensive guide, I‘ll explain everything you need to know about getting the most out of subdomains.

What is a Subdomain?

Simply put, a subdomain is an additional part of your main domain name that lets you segment your site.

For example:

store.yourwebsite.com

Here, ‘store‘ is the subdomain, ‘yourwebsite‘ is the primary domain, and ‘.com‘ is the top level domain (TLD).

You can make your subdomain anything you want! But keep it short and easy to remember.

Subdomains allow you to separate sections of your site for navigation and admin purposes. You can host different content, apps, or even entirely different websites on subdomains while keeping them under your main domain.

Why Use Subdomains?

Over the years, I‘ve seen companies use subdomains for all kinds of clever reasons. Here are some of the most popular ones:

  • Testing environments – Having a place like ‘test.yourdomain.com‘ lets you safely test changes before going live. As a developer, I can‘t stress enough how vital this is!

  • eCommerce stores – Many online shops use dedicated subdomains like ‘shop.yourdomain.com‘ since ecommerce needs complex setups. This keeps it separate from their content sites.

  • Mobile sites – Creating ‘m.yourdomain.com‘ allows you to serve a lean, fast mobile version of your site. Studies show these improve conversion rates by over 27%.

  • Country sites – You can use regional subdomains like ‘uk.yourdomain.com‘ or ‘fr.yourdomain.com‘ to target local audiences.

  • Sub-sections – Subdomains help organize disparate sections like ‘blog.yourdomain.com‘, ‘help.yourdomain.com‘, etc.

  • Isolation – Hosting forums, wikis or landing pages on their own subdomains improves security and speeds up load times.

  • Branding – Unique subdomains help you create niche campaigns around products, services or promotions.

See how useful they can be? With some creativity, the possibilities are endless!

How to Create a Subdomain

Here‘s a simple step-by-step process to create a subdomain:

  1. Login to your domain registrar account and visit the domain manager.

  2. Find the subdomain tools. For most registrars, look under ‘Domains‘ or ‘DNS‘.

  3. Enter your desired subdomain name (e.g. ‘demo123‘).

  4. Select your root domain in the menu.

  5. Click ‘Add‘ or ‘Create Subdomain‘ to register it.

It may take up to 48 hours for the subdomain to activate across global DNS servers. Once it‘s live, you can point it to any server or IP, just like your main domain.

Easy enough, right?

Now let‘s talk about an important aspect of subdomains – how they affect your website‘s SEO…

Subdomains vs Subdirectories for SEO

Over the years, I‘ve noticed subdomains and subdirectories confuse a lot of people when it comes to SEO. But it‘s actually quite simple:

Subdomains are seen as separate sites, while subdirectories are just files under your root domain.

Subdomains and SEO

  • Search engines have to crawl and index subdomains separately from the main site. More work!

  • Link signals like backlinks DON‘T get shared between subdomains and the parent domain.

  • Each subdomain starts with zero authority and must build rankings for keywords from scratch.

Because of this, I don‘t recommend creating subdomains just for SEO. Only use them if you have a very specific reason, like targeting a separate audience.

Subdirectories and SEO

  • Subdirectories are seen as part of your main site. Everything gets crawled and indexed together.

  • Link signals are shared site-wide, helping your whole domain.

  • New subdirectories can benefit from authority your main site has accumulated.

In most cases, subdirectories are better for SEO unless you want to deliberately isolate a section.

I hope this clears up how subdomains and subdirectories impact SEO!

Conclusion

Phew, that was a lot of info! Let‘s recap:

  • Subdomains help you segment your site for organization and isolation.

  • Use them strategically for things like mobile sites, country targeting, branding, etc.

  • Be mindful of how subdomains and subdirectories affect SEO.

  • For most sites, subdirectories are ideal unless you have a specific subdomain need.

I hope this guide gives you a solid understanding of how to master subdomains on your website! Let me know if you have any other questions.

Chat soon!

Written by Jason Striegel

C/C++, Java, Python, Linux developer for 18 years, A-Tech enthusiast love to share some useful tech hacks.