AAAA is a domain name record, which 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 where each IP address consists of four sets of decimal numbers which range from 1 to 255 e.g. 18.104.22.168. In comparison, an IPv6 address has 8 groups of four hexadecimal digits - which range from 0 to 9 and from A to F. The reason for this modification is the considerably smaller range of unique IPs that the current system supports and also 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 forward a domain to a server that uses such an address, you will need to set up an AAAA record for it, and not the widespread A record, which is an IPv4 address. The 2 records deliver the same exact function, yet different notations are used, to identify the two forms of addresses.