AAAA is a domain name record, that is essentially the IPv6 address of the server where the domain name is hosted. The IPv6 system was introduced to replace the present IPv4 system in which every single Internet protocol address comprises of four sets of decimal digits between 1 to 255 e.g. 18.104.22.168. In comparison, an IPv6 address has 8 groups of 4 hexadecimal numbers - ranging from 0 to 9 and from A to F. The cause of this transformation is the substantially smaller range of unique IPs which the existing system supports as well as the fast increase of units which are connected to the Internet. A good example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you wish to point a domain name to a server which uses this type of an address, you'll have to set up an AAAA record for it, and not the commonly used A record, which is an IPv4 address. The 2 records deliver the exact same function, but different notations are used, to differentiate the two types of addresses.