AAAA is a domain name record, which is essentially the IPv6 address of the server in which the domain name is hosted. The IPv6 system was introduced to replace the existing IPv4 system where each and every IP address is comprised of 4 groups of decimal digits which range from 1 to 255 e.g. 220.127.116.11. In comparison, an IPv6 address features 8 groups of four hexadecimal numbers - ranging from 0 to 9 and from A to F. The main reason for this change is the substantially smaller range of unique IPs which the current system supports as well as the fast increase of devices that are connected to the Internet. A good example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you need to point a domain name to a web server that uses this sort of an address, you will have to set up an AAAA record for it, not the widespread A record, that is an IPv4 address. The 2 records have the exact same function, yet different notations are used, in order to differentiate the two sorts of addresses.