AAAA is a domain record, that's basically the IPv6 address of the server in which the domain is hosted. The IPv6 system was intended to replace the current IPv4 system where every IP is comprised of 4 groups of decimal numbers between 1 to 255 e.g. 18.104.22.168. In contrast, an IPv6 address includes eight groups of 4 hexadecimal digits - which range from 0 to 9 and from A to F. The reason behind this transformation is the considerably smaller amount of unique IPs that the existing system supports as well as the fast increase of products that are connected to the world wide web. An example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you want to point a domain name to a server that uses this kind of an address, you have to set up an AAAA record for it, not the widely used A record, that is an IPv4 address. The two records provide the very same function, but different notations are used, to differentiate the two types of addresses.