AAAA is a domain address record, that is essentially the IPv6 address of the server where the domain is hosted. The IPv6 system was designed to replace the present IPv4 system in which each IP is comprised of four groups of decimal digits ranging from 1 to 255 e.g. 18.104.22.168. On the other hand, an IPv6 address includes eight sets of four hexadecimal digits - from 0 to 9 and from A to F. The cause of this change is the significantly smaller selection of unique IPs which the present system supports as well as the quick increase of gadgets which are connected to the world wide web. A good example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you wish to forward a domain address to a machine that uses this kind of an address, you will need to set up an AAAA record for it, not the widely used A record, that is an IPv4 address. Both records have the same exact function, yet different notations are used, in order to differentiate the two forms of addresses.