A subdomain is a domain that is part of a larger domain; the only domain that is not also a subdomain is the root domain.
It's a subsection of your website that can exist as a new website without a new domain name. Use subdomains to create memorable URLs for different content areas of your site
In this tutorial, we’ll show you how to setup a subdomain.
1) Login to your Obsidian Hosting Account
2) Access cPanel
3) Once in cPanel, scroll down under Domains and click Subdomains.