AAAA is a domain address record, which is in essence the IPv6 address of the web server where the domain is hosted. The IPv6 system was introduced to replace the current IPv4 system where each and every IP address consists of four groups of decimal digits which range from 1 to 255 e.g. 18.104.22.168. However, an IPv6 address includes 8 groups of four hexadecimal numbers - which range from 0 to 9 and from A to F. The cause of this modification is the significantly smaller amount of unique IPs which the current system supports and also the speedy increase of devices that are connected to the Internet. An example of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you wish to forward a domain name to a machine that uses such an address, you will have to create an AAAA record for it, not the commonly used A record, that is an IPv4 address. Both records deliver the same exact function, yet different notations are used, so as to separate the two sorts of addresses.