Each device that's connected to the world wide web has a special identifier known as IP (Internet Protocol) address. This includes personal computers, web servers, smartphones, switches, and so on. The pool of IPs, that was introduced at first, has already been distributed, hence the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain which opens a site comes with an IP record, which is the address of the server where it is hosted. Using the IPv4 system, the record is called A and it comprises of four groups of numbers from 1 to 255 divided using a dot, while with the IPv6 system it's called AAAA and it is comprised of eight groups of hexadecimal numbers i.e. this kind of records use digits from 0 to 9 and letters from A to F. A good example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format is designed for a substantially greater number of IPs when compared with the IPv4 format.