What Is A Subdomain? When Do You Need It?

If you’ve only owned your domain or website for a short amount of time, you might not be familiar with what a subdomain is and its use when it comes to organizing. You’re probably more familiar with the more traditional way of organizing websites, which is through subdirectories.

While sub directories can certainly be useful, they don’t offer you the same amount of freedom and flexibility as a subdomain does. You can even set up a whole different website under your domain and have each one serves varying purposes.

What Is A Subdomain?

Well, a subdomain is anything that goes before your main URL and domain name. Let’s say your URL is example.com. Well, if you added ‘blog’ in front, making it blog.example.com, then the blog is the subdomain. 

This can get a little confusing if you aren’t familiar with how URLs work. You see, the ‘.com’ portion of the URL is what’s called a Top-Level-Domain or TLD, and the ‘example’ part is the Second-Level-Domain or SLD. As such, a subdomain is a sub-section of the SLD, which is the domain you purchase from a domain registrar.

This can get a little confusing if you aren’t familiar with how URLs work. You see, the ‘.com’ portion of the URL is what’s called a Top-Level-Domain or TLD, and the ‘example’ part is the Second-Level-Domain or SLD. As such, a subdomain is a sub-section of the SLD, which is the domain you purchase from a domain registrar.

Subdomain Vs. Sub directory

On the other hand, subdirectories put that extra bit at the end of the URL instead of the start. Using the above URL example, a subdirectory would look like example.com/blog with that blog at the end being a subdirectory. 

The best way to think of it is that the subdirectory is like a folder inside your hard drive, while a subdomain is another hard drive in your computer, with your computer itself being your domain.

Impact Of Subdomain On SEO

According to Google, subdomains are treated the same as subdirectories. That means that if Site A uses subdomains and Site B uses subdirectories, they both would rank the same for keywords assuming they had identical content, right? Well, not so much.

As it turns out, Google treats subdomains as different and apart from the root domain or SLD. So, if you are trying to rank for a specific keyword but spread that keyword across an SLD and subdomain, you dilute that keyword. Therefore, using a subdomain is actually bad for SEO. Simply put, subdomains still offer a large amount of value beyond any SEO issues you might run into.

Conclusion

Another excellent option for subdomains is to use them for expanding into foreign markets from low-cost domain reseller is where you might not necessarily be using the same keywords or the same language.