AAAA is a domain address record, that is essentially the IPv6 address of the web server in which the domain is hosted. The IPv6 system was introduced to replace the existing IPv4 system in which each IP consists of four groups of decimal digits which range from 1 to 255 e.g. 18.104.22.168. In comparison, an IPv6 address features 8 sets of 4 hexadecimal digits - which range from 0 to 9 and from A to F. The main reason for this modification is the significantly smaller amount of unique IPs that the current system supports as well as the quick increase of products that are connected to the Internet. An example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you need to direct a domain to a web server which uses such an address, you have to create an AAAA record for it, and not the widely used A record, that is an IPv4 address. Both records deliver the same exact function, yet different notations are used, in order to distinguish the two types of addresses.