AAAA is a domain record, which is basically the IPv6 address of the web server in which the domain is hosted. The IPv6 system was designed to replace the present IPv4 system where each and every IP address comprises of 4 groups of decimal digits ranging from 1 to 255 e.g. 5.168.208.143. In comparison, an IPv6 address has 8 groups of four hexadecimal numbers - ranging from 0 to 9 and from A to F. The reason behind this change is the substantially smaller number of unique IPs which the existing system supports and the speedy increase of devices which 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 forward a domain to a web server that uses such an address, you will need to set up an AAAA record for it, not the commonly used A record, that is an IPv4 address. The two records have the very same function, yet different notations are used, to differentiate the two sorts of addresses.