Subdomain vs. Subdirectory: What’s the Difference

Domain name, index file, add-on domain, subdomain, subdirectory – the terminology related to website structure can be mind boggling. Here’s an explanation of the Domain Name System (DNS) that will help you sort this out.

First thing to understand is that the Internet’s domain name system has a tree structure or hierarchy, with each node on the tree being a domain name.

A folder contained inside another folder is called a subdirectory (aka  subfolder) of that folder. Together, the folders form a hierarchy, or tree structure.

What’s the difference between a subdomain and a subdirectory?

A subdomain is a domain that is part of a larger domain. For example, vegetablegardening.mywebsite.com is a subdomain of the mywebsite.com domain.

You’ll notice that a subdomain (vegetablegardening) comes before the  main domain name (mywebsite.com).

In contrast, a  subdirectory (aka subfolder) comes after the main domain name.

So a subdirectory (aka subfolder) would  look like mywebsite.com/vegetablegardening.

Which is better for SEO?

For purposes of search engine optimization (SEO), Google treats a subdomain as a separate entity. So if the main domain (mywebsite.com) is just doing great – lots of page rank, backlinks, and authority, none of that will be of any help to vegetablegardening.mywebsite.com.

Subdirectories will benefit when other parts of the same domain are doing well; so that mywebsite.com can “pass through” some of its page rank and authority to mywebsite.com/vegetablegardening.

This is one of those things that SEO experts like to debate over – so be prepared for different opinions on this.

Related posts:

1. Subdomain vs. Subdirectory: What's the Difference
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3. What's the difference between a subdomain and a subdirectory?
4. What’s the difference between an add-on domain and a sub-domain?
5. What's the difference between an add-on domain and a sub-domain?