AAAA is a domain record, that's essentially the IPv6 address of the server where the domain name is hosted. The IPv6 system was intended to replace the existing IPv4 system where every IP is made up of four groups of decimal numbers ranging from 1 to 255 e.g. 18.104.22.168. In comparison, an IPv6 address has 8 groups of four hexadecimal numbers - which range from 0 to 9 and from A to F. The cause of this transformation is the tremendously smaller number of unique IPs which the current system supports and the quick increase of products that are connected to the world wide web. A good example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you'd like to forward a domain address to a web server that uses such an address, you'll have to set up an AAAA record for it, and not the widely used A record, that is an IPv4 address. Both records provide the very same function, yet different notations are used, so as to differentiate the two sorts of addresses.