AAAA is a domain name record, that's in essence the IPv6 address of the server in which the domain name is hosted. The IPv6 system was designed to replace the existing IPv4 system where every IP comprises of 4 sets of decimal digits which range from 1 to 255 e.g. 220.127.116.11. On the other hand, an IPv6 address includes 8 sets of 4 hexadecimal digits - from 0 to 9 and from A to F. The reason behind this change is the substantially smaller range of unique IPs which the current system supports and the speedy increase of units which are connected to the Internet. An example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you need to forward a domain name to a server 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 2 records have the exact same function, but different notations are used, in order to distinguish the two sorts of addresses.