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 introduced to replace the present IPv4 system where each and every IP address is made up of four sets of decimal numbers which range from 1 to 255 e.g. 126.96.36.199. In comparison, an IPv6 address includes eight sets of four hexadecimal numbers - from 0 to 9 and from A to F. The cause of this change is the tremendously smaller selection of unique IPs the present system supports and the rapid increase of units which are connected to the Internet. A good example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you wish to forward a domain name to a server that uses this kind of an address, you will have to set up an AAAA record for it, not the widespread A record, which is an IPv4 address. The two records provide the very same function, but different notations are used, so as to distinguish the two types of addresses.