AAAA is a domain name record, that is basically the IPv6 address of the web server in which the domain is hosted. The IPv6 system was intended to replace the present IPv4 system in which every single IP address is made up of four sets of decimal numbers ranging from 1 to 255 e.g. 18.104.22.168. In comparison, an IPv6 address has 8 groups of 4 hexadecimal digits - ranging from 0 to 9 and from A to F. The cause of this change is the considerably smaller amount of unique IPs which the current system supports and the rapid increase of gadgets that are connected to the world wide web. An illustration of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you want to point a domain address to a server that uses such an address, you need to create an AAAA record for it, and not the commonly used A record, which is an IPv4 address. Both records provide the exact same function, yet different notations are used, to differentiate the two types of addresses.