AAAA is a domain name record, which is essentially the IPv6 address of the web server where the domain name is hosted. The IPv6 system was designed to replace the existing IPv4 system where each and every IP consists of four sets of decimal numbers between 1 to 255 e.g. 22.214.171.124. However, an IPv6 address features eight sets of 4 hexadecimal digits - which range from 0 to 9 and from A to F. The cause of this transformation is the substantially smaller selection of unique IPs which the existing system supports and also the fast increase of gadgets that are connected to the Internet. An illustration of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you wish to forward a domain name to a machine that uses this sort of an address, you have to set up an AAAA record for it, not the commonly used A record, that is an IPv4 address. Both records have the exact same function, yet different notations are used, in order to distinguish the two forms of addresses.