AAAA is a domain name record, which is in essence the IPv6 address of the web server where the domain name is hosted. The IPv6 system was intended to replace the existing IPv4 system in which every single IP is made up of 4 groups of decimal digits between 1 to 255 e.g. 5.168.208.143. However, an IPv6 address has eight groups of 4 hexadecimal numbers - ranging from 0 to 9 and from A to F. The reason behind this change is the significantly smaller number of unique IPs which the current system supports and also the fast increase of products that are connected to the Internet. An illustration of an IPv6 address would be 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you wish to point a domain address to a server which uses this kind of an address, you will need to set up an AAAA record for it, and not the widely used A record, that is an IPv4 address. The 2 records have the same exact function, yet different notations are used, to identify the two types of addresses.