Subdomains are domains that are a part of a larger domain. Taking the file analogy we used earlier in this course, if your domain is a folder, then a subdomain is a folder inside of it. In fact, the only domain that is not a subdomain is the root domain. For example course.exam.com is a subdomain of exam.com which is in turn a subdomain of com which is the root domain. As you may have noticed subdomains are all separated by a ‘.’. So a subdomain is just a another domain.
So what does this mean for you as a designer. The reason that it is relevant is while it is a part of your main domain, if you set up a subdomain on it, you can create an entirely new site on your subdomain. So, say I run a property management site and I have a WordPress instance on my main domain myco.com where I feature all of my properties. Well, while I decide to feature all of my properties on the main site I still want each property to be completely separate from the others. I want them to have their own look and feel, with their own functionality, and maybe I want my property managers to be admins for their property but not any of the others. I would use subdomains to accomplish this. If I made a subdomain for each property I could have a different WordPress instance on each, with their own themes, plugins, and users. Essentially each is its own separate site but they are all still connected under my main domain.
