AAAA is a domain record, that's basically the IPv6 address of the web server where the domain is hosted. The IPv6 system was introduced to replace the current IPv4 system in which every IP address comprises of 4 groups of decimal numbers which range from 1 to 255 e.g. 126.96.36.199. In contrast, an IPv6 address features 8 groups of 4 hexadecimal digits - ranging from 0 to 9 and from A to F. The main reason for this change is the substantially smaller number of unique IPs that the current system supports and the rapid increase of units which are connected to the world wide web. An illustration of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you need to point a domain address to a server which uses this sort of an address, you have to create an AAAA record for it, not the widespread A record, that is an IPv4 address. Both records have the same exact function, but different notations are used, so as to differentiate the two forms of addresses.