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 present IPv4 system in which every IP address consists of four sets of decimal numbers which range from 1 to 255 e.g. 5.168.208.143. However, an IPv6 address features eight groups of four hexadecimal digits - from 0 to 9 and from A to F. The reason for this modification is the tremendously smaller number of unique IPs that the present system supports and the rapid increase of units which are connected to the Internet. A good example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you need to point a domain to a machine which uses this sort of an address, you will have to set up an AAAA record for it, and not the commonly used A record, that is an IPv4 address. The 2 records have the same exact function, but different notations are used, to differentiate the two types of addresses.