What Is Subdomain? Domain Glossary

Why it matters

Subdomains let one owner run several sites or services from a single name. A company can host its app at app.example.com and its help center at help.example.com. For buyers, a subdomain on a platform is not the same as owning a domain, because the platform owner controls it. Sellers should note that subdomains add no resale value to the root name. Common mistake: a business builds its brand on a free subdomain, such as a site builder address, then finds it cannot move its search ranking or email to a real domain.

Source: cloudflare.com

Related terms

Domain name: A domain name is a human-readable address, such as example.com, that points to a website, email server, or other internet service through the Domain Name System. It replaces numeric IP addresses that people cannot easily remember.
DNS record: A DNS record is an instruction stored on a domain's authoritative name server. It tells the internet where to send web, email, or other traffic for that domain.
Second-level domain (SLD): The part of a domain name directly to the left of the top-level domain. In example.com, "example" is the second-level domain. It is the label a registrant actually chooses and registers.
CNAME record: A DNS record that makes one name an alias of another name. A visitor to the alias is sent to the target name's address. It is often used for subdomains such as www.
Top-level domain (TLD): The top-level domain is the last label in a domain name, the part after the final dot. In icann.org, the TLD is org. It sits at the top of the naming hierarchy of the Domain Name System.

All 205 terms

Why it matters

Buying or selling a domain?