An AAAA record is an IP in the recently introduced IPv6 format and it is comprised of eight different groups of hexadecimal digits, unlike the IPv4 IPs, that include 4 groups of digits between 1 and 255. An illustration of an IPv6 address would be 3014:0d43:23a3:2354:1320:8f3b:2635:3254 and with this format the sheer number of IPs which can be created is many times greater than the number of the IPv4 addresses. Each and every domain has its web hosting server IP address as a record and in essence, that record informs the domain name where the website for it is. Depending on the system that the service provider uses, the record is going to be called A (IPv4) or AAAA (IPv6). Changing this record permits you to host your site with one company and your email messages with a different one, so if you choose to use such a redirection to point a domain name to a server that uses an IPv6 address, you'll need to create an AAAA record for it.