Subdomain

A prefix to a domain name (e.g., "blog.example.com") created for free via DNS.

A subdomain is a domain that is a prefix to a main domain name, separated by a dot — for example, "blog.example.com" or "shop.example.com." Subdomains are free to create (no registration required) and are controlled by the domain owner via DNS records. Subdomains are commonly used to organize website sections, run separate applications, or create vanity URLs.