Every single device which is connected to the Internet has a unique identifier referred to as IP (Internet Protocol) address. This includes computers, web servers, smart phones, switches, and so on. The pool of IP addresses, which was introduced at first, has already been distributed, hence the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain that opens an internet site comes with 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 comprises of four groups of numbers from 1 to 255 separated by a dot, while within the IPv6 system it's called AAAA and it is made up of 8 groups of hexadecimal numbers i.e. this kind of records use numbers 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 can handle a significantly greater amount of IPs in comparison with the IPv4 format.