AAAA is a domain address record, that is in essence the IPv6 address of the web server in which the domain name is hosted. The IPv6 system was intended to replace the current IPv4 system where every single IP address comprises of 4 sets of decimal numbers which range from 1 to 255 e.g. 126.96.36.199. In comparison, an IPv6 address has 8 groups of four hexadecimal digits - ranging from 0 to 9 and from A to F. The cause of this modification is the considerably smaller number of unique IPs which the existing system supports and also the quick increase of devices which 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 want to forward a domain address to a web server that uses this sort of an address, you will have to set up an AAAA record for it, not the widespread A record, that is an IPv4 address. Both records have the exact same function, yet different notations are used, in order to separate the two sorts of addresses.