AAAA is a domain record, which is basically the IPv6 address of the server in which the domain name is hosted. The IPv6 system was introduced to replace the present IPv4 system in which each IP address is comprised of 4 groups of decimal digits between 1 to 255 e.g. 5.168.208.143. In comparison, an IPv6 address has eight sets of four hexadecimal digits - which range from 0 to 9 and from A to F. The reason behind this change is the considerably smaller selection of unique IPs which the existing system supports as well as the fast increase of products which are connected to the Internet. A good example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you'd like to direct a domain to a machine that uses this type of an address, you need to set up an AAAA record for it, not the commonly used A record, which is an IPv4 address. The 2 records deliver the same exact function, but different notations are used, in order to differentiate the two forms of addresses.