AAAA is a domain name record, which is basically the IPv6 address of the server where the domain is hosted. The IPv6 system was intended to replace the current IPv4 system where every IP address is comprised of 4 sets of decimal digits between 1 to 255 e.g. 18.104.22.168. However, an IPv6 address includes eight groups of 4 hexadecimal digits - which range from 0 to 9 and from A to F. The main reason for this change is the considerably smaller amount of unique IPs that the current system supports and also the fast increase of products 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 machine which uses this type of an address, you need to set up an AAAA record for it, and not the widely used A record, which is an IPv4 address. The two records have the exact same function, yet different notations are used, in order to differentiate the two forms of addresses.