AAAA is a domain name record, which is basically the IPv6 address of the web server where the domain is hosted. The IPv6 system was designed to replace the present IPv4 system where each and every IP comprises of 4 groups of decimal numbers which range from 1 to 255 e.g. 126.96.36.199. In comparison, an IPv6 address has 8 sets of 4 hexadecimal numbers - from 0 to 9 and from A to F. The main reason for this modification is the significantly smaller selection of unique IPs which the current system supports and also the speedy increase of devices which are connected to the world wide web. A good example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you want to direct a domain name to a machine which uses this type of an address, you will have to create an AAAA record for it, and not the widespread A record, which is an IPv4 address. The 2 records deliver the exact same function, yet different notations are used, to differentiate the two forms of addresses.