Subdomains are extensions of your domain name that you can forward to URLs or point to IP addresses and directories within your hosting account.
It’s easy to create a memorable Web address for unique content areas of your Website by using subdomains. For example, you could create a subdomain for pictures on your Website called "pics" that is accessible through the URL pics.coolexample.com in addition to www.coolexample.com/pics.
You can add up to 100 subdomains per domain name. You can also add multiple levels of subdomains. For instance, you can add info.blog.coolexample.com to delve into an even more specific area of interest on your Website. Each subdomain can be up to 25 characters long.