AAAA is a domain address record, which is essentially the IPv6 address of the web server where the domain name is hosted. The IPv6 system was intended to replace the present IPv4 system in which each IP consists of 4 sets of decimal digits between 1 to 255 e.g. 18.104.22.168. However, an IPv6 address features eight groups of four hexadecimal digits - ranging from 0 to 9 and from A to F. The cause of this change is the substantially smaller range of unique IPs which the current system supports and the quick increase of devices that are connected to the Internet. A good example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you'd like to forward a domain address to a machine which uses this sort of an address, you will have to create an AAAA record for it, not the widely used A record, that is an IPv4 address. The two records deliver the exact same function, yet different notations are used, to differentiate the two types of addresses.