Every device that's connected to the world wide web has a unique identifier known as IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, etc. The pool of IP addresses, which was introduced at first, has been distributed, hence the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain name that opens an internet site has an IP record, that is the address of the server where it is hosted. With the IPv4 system, the record is called A and it is comprised of four groups of numbers from 1 to 255 divided with a dot, while with the IPv6 system it's called AAAA and it consists of eight groups of hexadecimal numbers i.e. this type of records use digits from 0 to 9 and letters from A to F. An example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format works with a significantly larger amount of IPs when compared with the IPv4 format.