AAAA is a domain record, that is basically the IPv6 address of the server where the domain name is hosted. The IPv6 system was designed to replace the existing IPv4 system where each IP address is made up of four groups of decimal digits ranging from 1 to 255 e.g. 126.96.36.199. On the other hand, an IPv6 address has 8 groups of 4 hexadecimal digits - which range from 0 to 9 and from A to F. The reason behind this transformation is the considerably smaller number of unique IPs which the present system supports and also the rapid increase of devices that are connected to the world wide web. An illustration of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you need to direct a domain address to a web server which uses this sort of an address, you will have to set up an AAAA record for it, not the commonly used A record, that is an IPv4 address. The two records provide the very same function, yet different notations are used, in order to differentiate the two types of addresses.