CNAME

Canonical Name

A type of DNS (Domain Name System) record that creates an alias for one domain name to point to another. Think of it as a nickname or a shortcut.

How CNAME works

• When a CNAME record is set up, it tells the DNS system that any requests for the alias domain should be directed to the canonical (real) domain. Usage examples:
  • www subdomain: Pointing www.example.com to example.com
  • Subdomains for services: Pointing blog.example.com to a blogging platform’s domain
  • Multiple services on one IP: Using different domain names for different services hosted on the same server
• The canonical domain usually has an A record associated with it, which points to the actual IP address of the server hosting the content.

A website hosted at example.com can also be made accessible via www.example.com by creating a CNAME (Canonical Name) record for the latter, pointing it to the former. When a user types www.example.com into their browser, the Domain Name System (DNS) follows the CNAME record and directs them to the content hosted at the root domain, example.com. A CNAME record always points to another domain name, not directly to an IP address. Additionally, it cannot be used for the root domain itself, and excessive chaining of CNAME records can negatively impact performance.

• Abbreviation: CNAME