Subdomains are extensions of domain name that you can forward to URLs or point to IP addresses and directories within the hosting account or different servers. Sub domains function separately from your main domain. We can create areas of a website by using subdomains.
You can create a subdomain for a blog on site called "Blog" that is accessible through the URL – blog.tutorialspoint.com in addition to the already existing www.tutorialspoint.com/blog.
We can add endless subdomains per domain name in theory. We can also add multiple levels of subdomains. For instance, you can add info.blog.tutorialspoint.com to delve into an even more specific area of interest on the site. Each subdomain can be up to 25 characters long.