A Fully Qualified Domain Name (FQDN), or Absolute Domain Name, is a complete domain name that identifies a host or server.
The format of a FQDN is
[hostname].[domain].[tld]., which can be split up into four components: hostname, domain, top-level domain (TLD), and a trailing period that represents the root of the DNS hierarchy. The trailing period may not be present outside of setting DNS records, since the final period is assumed to be present in FQDN.
You read FQDNs from right to left, with the right representing the top level (general) and the left representing the lower levels (specific).
FQDNs are unambiguous since they specify the exact location in the DNS tree hierarchy.
You can point an FQDN to a Droplet’s IP address using a DNS record. For example, with an IPv6 address, you could use a AAAA record that points the FQDN to the Droplet’s IPv6 address. On DigitalOcean, if you name your Droplet the same as your FQDN upon creation, then we automatically generate a PTR record for you.