A CNAME record is an abbreviation for Canonical Name record and is a type of resource record in the Domain Name System (DNS) used to specify that a domain name is an alias for another domain, the “canonical” domain. All information, including subdomains, IP addresses, etc, are defined by the canonical domain. This is convenient when running multiple services (like an FTP server and a webserver; each running on different ports) from a single IP address. You can, for example, point ftp.example.com and www.example.com to the A record example.com, which in turn points to the IP-address. Then, if you ever need to change the IP-address, you only have to change it in one place (A record). CNAME records must always be pointed to another domain name, never to an IP-address.