AAAA is a domain name 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 each IP is made up of 4 sets of decimal digits ranging from 1 to 255 e.g. 22.214.171.124. On the other hand, an IPv6 address includes eight groups of 4 hexadecimal digits - from 0 to 9 and from A to F. The reason behind this transformation is the considerably smaller amount of unique IPs which the present system supports and the fast increase of devices which are connected to the Internet. An example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you'd like to direct a domain name to a server which uses this sort of an address, you will need to create an AAAA record for it, and not the widely used A record, which is an IPv4 address. Both records have the same exact function, yet different notations are used, to separate the two forms of addresses.