AAAA is a domain name record, that's basically the IPv6 address of the server where the domain name is hosted. The IPv6 system was designed to replace the present IPv4 system in which every Internet protocol address comprises of 4 sets of decimal numbers ranging from 1 to 255 e.g. 5.168.208.143. However, an IPv6 address includes 8 groups of four hexadecimal digits - ranging from 0 to 9 and from A to F. The reason for this change is the considerably smaller range of unique IPs which the current system supports and the fast increase of devices that are connected to the Internet. An illustration of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you'd like to forward a domain to a web server which uses this sort of an address, you'll have to create an AAAA record for it, not the widespread A record, which is an IPv4 address. The two records deliver the exact same function, yet different notations are used, to separate the two types of addresses.