AAAA is a domain name record, which is basically the IPv6 address of the server in which the domain name is hosted. The IPv6 system was designed to replace the current IPv4 system in which every Internet protocol address comprises of four sets of decimal numbers between 1 to 255 e.g. 18.104.22.168. In comparison, 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 considerably smaller range of unique IPs that the existing system supports and the quick increase of products which are connected to the world wide web. A good example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you want to forward a domain to a server that uses this sort of an address, you have to set up an AAAA record for it, not the widely used A record, which is an IPv4 address. The two records deliver the same exact function, yet different notations are used, so as to differentiate the two forms of addresses.