AAAA is a domain name record, that's essentially the IPv6 address of the server where the domain is hosted. The IPv6 system was introduced to replace the existing IPv4 system in which each and every IP address consists of 4 groups of decimal digits ranging from 1 to 255 e.g. 184.108.40.206. In comparison, an IPv6 address features 8 groups of four hexadecimal numbers - ranging from 0 to 9 and from A to F. The reason for this modification is the substantially smaller range of unique IPs which the existing system supports as well as the quick increase of gadgets 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 address to a server that uses this sort of an address, you need to create an AAAA record for it, not the widespread A record, that is an IPv4 address. The two records deliver the same exact function, but different notations are used, to identify the two types of addresses.