AAAA is a domain name record, that is in essence the IPv6 address of the server in which the domain name is hosted. The IPv6 system was intended to replace the present IPv4 system where every IP address is made up of 4 sets of decimal digits which range from 1 to 255 e.g. 5.168.208.143. On the other hand, an IPv6 address features eight sets of 4 hexadecimal digits - from 0 to 9 and from A to F. The main reason for this change is the significantly smaller amount of unique IPs which the existing system supports as well as the fast increase of gadgets that are connected to the world wide web. An illustration of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you want to forward a domain address to a server that uses this kind of an address, you'll have to create an AAAA record for it, and not the widely used A record, that is an IPv4 address. Both records have the exact same function, but different notations are used, in order to distinguish the two forms of addresses.
