What Does Subdomain Mean?

A subdomain is a domain that is a part of a larger domain under the Domain Name System (DNS) hierarchy. It is used as an easy way to create a more memorable Web address for specific or unique content with a website. For example, it could make it easier for users to remember and navigate to the picture gallery of a site by placing it in the address gallery.mysite.com, as opposed to mysite.com/media/gallery. In this case, the subdomain is gallery.mysite, whereas the main domain is mysite.com.

Techopedia Explains Subdomain

A subdomain is basically a child domain under a larger parent domain name. In the larger scheme of the Domain Name System, it is considered a third-level domain used to organize site content. In the Web address example above (gallery.mysite.com), the suffix “.com” is the first-level domain, “mysite” is the second-level domain and “gallery” is the third-level domain.