AAAA is a domain address record, that's basically the IPv6 address of the web server where the domain name is hosted. The IPv6 system was introduced to replace the existing IPv4 system where every IP consists of four sets of decimal digits between 1 to 255 e.g. 18.104.22.168. On the other hand, an IPv6 address has eight groups of 4 hexadecimal digits - which range from 0 to 9 and from A to F. The reason behind this change is the tremendously smaller selection of unique IPs the present 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 address to a server that uses this kind of an address, you have to set up an AAAA record for it, and not the commonly used A record, that is an IPv4 address. The 2 records have the exact same function, but different notations are used, so as to identify the two types of addresses.